Told from the points of view of both the Baltimore homicide and narcotics detectives and their targets, the series captures a universe in which the national war on drugs has become a permanent, self-sustaining bureaucracy, and distinctions between good and evil are routinely obliterated.

Seasons

Season	Episodes	Release date	Rating
Season 1 On the drug-infested streets of West Baltimore, there are good guys and there are bad guys. Sometimes you need more than a badge to tell them apart. Season 1 follows a single sprawling drug and murder investigation in Baltimore — one that culminates in a complex series of dangerous wiretaps and s…	13	2002-06-02	8.1
Season 2 McNulty's on harbor patrol. Daniels is in the police-archives dungeon. Prez is chafing in the suburbs. Greggs has a desk job. The detail may be on ice, but corruption marches on . . . and a horrific discovery is about to turn the Baltimore shipping port inside out. Setting up in the wake of the f…	12	2003-06-01	7.9
Season 3 The heat is on in Baltimore. The drug war is being lost, bodies are piling up, and a desperate mayor wants the tide turned before the election. But the police department hasn't got any answers. Wiretaps haven’t worked. Neither have stakeouts or street busts. With the demolition of the Franklin Te…	12	2004-09-19	8.2
Season 4 In the projects. On the docks. In City Hall. And now, in the schools. The places and faces change, but the game remains the same. A new story begins. This year, while expanding on storylines introduced in previous seasons — including the new vocations of several characters, the rise of a new drug…	13	2006-09-10	8.1
Season 5 In the projects. On the docks. In City Hall. In the schools. And now, in the media. The places and faces change, but the game remains the same. In the fifth — and final — season, the series expands its focus into the media — specifically the role of newspapers in big-city bureaucracy — as it foll…	10	2008-01-06	8.2

What's left behind the scenes

The scars on the faces of actors Michael K. Williams and Jamie Hector are real.
Michael B. Jordan played Wallace by drawing on his memories of growing up on the streets of Newark, New Jersey, where drugs could be bought on any corner in exactly the same way.
Omar is the only character in the series who avoids using profanity in his everyday speech. The actor who played the role, Michael Kenneth Williams, was even allowed to change his own lines if he discovered any accidental swear words in them.
When Dominic West was recording his audition tape at home in London, his girlfriend initially read the lines for the other characters in the scenes, and he couldn't stop laughing at her British accent. Eventually, West began performing the scenes himself, leaving pauses where the other characters' lines would be. The actor later admitted that he tried to imitate Robert De Niro. At first, the producers didn't like West's audition, but they later changed their minds and offered him the lead role. West was hesitant to sign the contract after seeing it covered five seasons, but his agent assured him that the series was unlikely to go beyond the first season. West signed the contract on the condition that he would have free time—for example, to star in Zack Snyder's historical action film '300' and to spend enough time with his family. These terms were accepted, which is why West's character appears very rarely on screen in the fourth season.
According to David Simon, the death of his character took a heavy toll on Idris Elba. Simon had to convince the actor that his character was written out of the series not because of a lack of acting talent, but that he had plenty of talent and would certainly be offered new roles in other projects. He proved to be right; Elba subsequently starred in the drama series 'Luther' (2010-2019) and came to be regarded as one of the most popular cast members of 'The Wire' (although not everyone agrees with this assertion).
In Season 1, Episode 8, at the 50-minute mark, a continuity error with a clock can be seen: the clock first shows 9:07, but after a cut to Kim, it shows 9:06, then after another cut, the clock shows 9:07 again.
The name of Russell Bell, nicknamed Stringer (played by Idris Elba), combined the names of two Baltimore drug lords—Stringer Reed and Roland Bell. His life has much in common with the story of Kenneth A. Jackson, who transitioned from drug trafficking to running a legal business.
Bubbles, played by Andre Royo, was based on a real person from Baltimore, a drug addict and police informant. Bubbles began working for the police back in the early 1960s after being arrested for robbery. Over the following decades, he remained an informant, handing over literally hundreds of criminals to the police and receiving $50 for each arrest. Thanks to his nearly photographic memory and his ability to blend in and seem like one of their own, he became one of the best police informants in the entire city. Eventually, he adopted the method mentioned in the series: Bubbles pretended to sell headwear, and he would offer hats of a specific color to those the police needed to arrest.
According to Sonja Sohn, she constantly forgot her lines during the filming of the first season, leading to numerous delays. This was because she had grown up in the ghetto herself and had witnessed instances of police brutality; consequently, she felt uncomfortable playing the role of a police officer.
Many episodic characters were played by actual police officers, politicians, and former criminals.
According to Andre Royo, the Mayor of Baltimore hated the show's creative team, believing they were giving the city a bad image. Furthermore, the mayor egged the police on against the film crew and the actors involved in the shoot, encouraging law enforcement to detain the filmmakers for any reason or no reason at all (any charge would do—from jaywalking to resisting lawful orders of law enforcement officers in the line of duty and loitering). Such blatantly biased treatment from the police inevitably affected the filming schedule, but Royo still remembers that time with warmth.
There was practically no improvisation during filming. The actors delivered the lines written in the script word for word, and any changes to the dialogue had to be discussed in advance with writer and producer David Simon and receive his approval.
Michael Kenneth Williams found Felicia Pearson in one of Baltimore's clubs. He invited her to the set, where he introduced her to the writers and producers; subsequently, screen tests were organized, and Pearson was offered a role in the series.
Chris Bauer wore special costumes that visually bulked up his figure for his role as Frank Sobotka.
By Michael Kenneth Williams' own admission, he struggled with drug addiction during the filming of the third season. Additionally, he experienced an identity crisis and was in a constant state of anxiety due to his own popularity in the role of Omar.
At the 41st minute of Season 1, Episode 4, while McNulty and Kim are walking down the street discussing the wiretap, a man with an envelope walks toward them, but he disappears after the cut.
Lance Reddick, who played Cedric Daniels, auditioned for the roles of Bank Moreland and Bubbles.
Once during filming in Baltimore, a local resident approached Andre Royo and, saying that based on his appearance he looked like he needed a fix, gave him a small bag of heroin. Royo kept the bag, calling it his 'street Oscar'.
The character of Sergeant Jay Landsman is based on a real Baltimore police sergeant. Jay Landsman himself even auditioned for the role, but ultimately played Lieutenant Dennis Malloy in the third season.