The cast of previous instalments returned for the film, with the additions of Gary Oldman, David Thewlis, Timothy Spall, and Emma Thompson, among others.

It is credited for marking a notable shift in the franchise's tone and directing style and is often regarded by critics and fans alike as the best Harry Potter film.

Reuniting with his best friends Ron Weasley and Hermione Granger, Harry learns that Sirius Black, a convicted supporter of Lord Voldemort, has escaped Azkaban Prison and intends to kill him.

One enters Harry's compartment, causing him to faint, but new Defense Against the Dark Arts teacher Remus Lupin repels it with a Patronus Charm.

He follows Professor Minerva McGonagall, Madam Rosmerta, and Minister Fudge and learns that Black is actually his godfather but divulged the Potters' whereabouts to Voldemort and murdered their mutual friend Peter Pettigrew.

[34][35] David Bradley appears as Argus Filch, Hogwarts' caretaker,[30] while Robert Hardy portrays Cornelius Fudge, the Minister for Magic.

[36] Pam Ferris portrays Aunt Marge, Vernon's sister;[37] Lee Ingleby plays Stan Shunpike, conductor of the Knight Bus;[38] and Jim Tavaré appears as Tom, innkeeper of The Leaky Cauldron, replacing Derek Deadman from the first film.

[45][46] Guillermo del Toro was approached to direct, but had envisioned a more Dickensian version of the stories, and was put off by the first two films which he found too "bright and happy and full of light".

[49] Warner Bros. then composed a three-name shortlist for Columbus's replacement, which consisted of Callie Khouri, Kenneth Branagh (who played Gilderoy Lockhart in Chamber of Secrets) and eventual selection Alfonso Cuarón in July 2002.

Cuarón stated that the character should look like "an uncle who parties hard on the weekends", so Temime preserved his gown "unkempt and more shabby than the other teachers’ robes.

Temime used tie-dyed silk that would float behind him while walking, which she considered "a much lighter look" that gave the character more energy, in contrast with the "heavy and majestic" costumes designed for Harris' portrayal of Dumbledore.

Production designer Stuart Craig and art director Gary Tomkins added constructions including a clock tower and a courtyard,[59] and the hospital wing was redesigned and rebuilt.

It was built on a large hydraulic platform with the help of the special effects department, "creaking and moving as if being continually buffeted by the wind" in order to appear almost alive.

[66] Incidentally, the Glenfinnan Viaduct railway, which was also featured in Chamber of Secrets, is opposite Loch Shiel and was used to film the sequences when the Dementor boarded the train.

"[56] Industrial Light & Magic (ILM) and Framestore handled the key visual effects shots for the film, while The Moving Picture Company, Cinesite, and Double Negative crafted additional VFX material.

The water test footage provided creative direction for the visual effects team, adding the intangible metaphysical quality Cuarón was seeking.

Visual effects supervisors Tim Burke and Roger Guyett, the Industrial Light & Magic VFX team, and Temime collaborated in the creation of dementors.

Cuarón said, "Once we worked out the physiology, the way his bones would actually move, we had to capture his personality, which is a mixture of regal elegance, particularly when he is flying, and the clumsy and greedy creature he becomes back on land."

Creature effects supervisor Nick Dudman created several practical hippogriffs for the production, while Burke and Guyett oversaw the creation of the computer-generated version.

[59] When it was announced that Cuarón would direct Prisoner of Azkaban, there was initial speculation that his collaborative composer Patrick Doyle (who would score the following film) would do the music.

[70] One of the new themes, "Double Trouble", was written during production for a children's choir to perform in Hogwarts's Great Hall in one of the film's earlier scenes.

For instance, after learning of Black's "betrayal" of Harry's parents, he shouts in anger "I'm gonna kill him",[78] whereas in the book he is "too stunned to move".

[81] Mattel released film tie-ins that included the Harry Potter Championship Quidditch board game and character action figures.

[82] Lego also expanded on its previous merchandising for the first two films with the release of sets that included the Knight Bus, Shrieking Shack and a new Hogwarts castle.

[91] Upon release, the film broke the record for a biggest single day in the United Kingdom's box office history making £5.3 million on a Monday.

The site's critical consensus reads, "Under the assured direction of Alfonso Cuarón, Harry Potter and the Prisoner of Azkaban triumphantly strikes a delicate balance between technical wizardry and complex storytelling.

"[108] The Hollywood Reporter called the film "a deeper, darker, visually arresting and more emotionally satisfying adaptation of the J.K. Rowling literary phenomenon," especially compared to the first two instalments.

"[115] Sean Smith from Newsweek said: "The Prisoner of Azkaban boasts a brand-new director and a bold new vision," and called the film "moving," praising the performances by the three main leads.

"[118] Screen Daily commented, "Cuaron delivers a genuinely spooky and emotionally involving adventure which gives the world of Potter much-needed character and atmosphere".

[121] Harry Potter and the Prisoner of Azkaban received two Academy Award nominations: Best Visual Effects and Best Original Score for John Williams.