In the film, Dilli, a recently released prisoner races-against-time to drive poisoned cops to a hospital while evading criminals in exchange for meeting his daughter Amudha.

The entire city's top ranked police officials fall unconscious after consuming spiked alcohol at the IG's retirement party.

Paalpandi, a corrupt cop (who was recruited by Stephen Raj, Zonal Head of Narcotics Division), pretends to be unconscious while giving information about the truck's location to the gangs.

Bejoy orders Napoleon, a constable, and a group of college students, detained due to drunk driving, to close all the possible exits to the commissioner's office and try to keep Anbu's gangsters outside, preventing them from taking the drugs and freeing Adaikalam's men.

After the success of Maanagaram (2017), director Lokesh Kanagaraj had rejected several offers from various production houses as he did not want to "succumb to the pressure of staying relevant in the industry by signing back-to-back projects".

[7] Eventually, he worked on the final draft that consisted of 45 pages and sent it to Prabhu's office, which Lokesh felt that "given the size of the script, he was perplexed when I handed it over to him".

[23] Arjun Das was chosen to play the main antagonist Anbu since Lokesh felt he had the powerful voice needed for the character.

[34][35] However, Lokesh in Srivatsan's interview to The Hindu, stated that Die Hard (1988) and Virumaandi (2004), served as additional references for Kaithi,[5] and had also credited them in the film.

[15] The setting of where the entire story takes place in a night, was also referenced from the filmography of directors Martin Scorsese and Quentin Tarantino.

He took the hostage scene in Die Hard as an example, where the "darkness made it very atmospheric" and concluded that "In a way, this film was a reverse of that situation, where the bad guys are locked inside a police station that is under siege".

[50] Prior to the scheduled release, the Tamil Nadu government denied permission to conduct early morning shows for the film and Bigil in concern of the increased ticket rates being levied by the exhibitors.

[58] It eventually received criticism from the exhibitors and distributors as the early digital premiere might lead to reducing number of footfalls in theatres.

[59] While producer S. R. Prabhu, attributed that the threat of piracy might be the reason for the 30-day window between theatrical and streaming run, many theatre owners opposed this.

[85] Calling it as a "tense and impressively shot action thriller", M. Suganth gave 4.5 stars (out of 5) in the review for The Times of India, and stated "Lokesh Kanagaraj gives us a pure genre film minus the frills, like songs and romance, that we are used to in Tamil cinema".

[86] Janani K of India Today gave four out of five stars stating, "Kaithi is a film that showcases filmmaking at its best" and praised Karthi's performance as "terrific and natural that one could literally picture a prisoner going through a tough time".

He further added that "Karthi's raw and intense performance, the film's taut screenplay and excellent technicality, along with awesome action scenes, makes Kaithi an edge-of-the seat thriller".

[89] Manoj Kumar R. of The Indian Express gave 3.5 stars (out of 5) stating, "Karthi has essayed his role in an almost self-effacing manner while allowing the space for other people's acts of courage in the narration to get their due screen time.

The director softly but firmly announces himself as a major new force in the commercial space of the Tamil film industry, which still largely feeds on the narrow definition of mainstream entertainment.

[93] Calling it as "brilliant" and "engaging thriller", Anupama Subramanian of Deccan Chronicle gave four out of five, saying "Kaithi with its solid story combined with outstanding performances and flawless making is set to stand the test of time".

[94] The News Minute-based editor-in-chief, Priyanka Thirumurthy, gave four out of five stating "There is no star in Kaithi, as director Lokesh shows that a hero is anyone who goes beyond thinking about just himself.

"[95] Baradwaj Rangan wrote for Film Companion, "Kaithi is certainly a sturdy vehicle for Karthi, who – as Theeran Adhigaaram Ondru so memorably demonstrated – is one of our few actors who can do both Clark Kent (through his face) and Superman (through his stocky frame).

There's a fantastic "mass" scene, set around a swimming pool, where Dilli stuffs himself with biriyani – it's a stunning few minutes of a purely physical performance.

[110] Lokesh, in an interview with an online portal, stated that Vijay, who signed him for directing Master (2021), during the post-production of Kaithi, had watched the final rushes of the film before its release.

[112][113] Arjun Das, who played the main antagonist, Anbu, received praise for his characterisation and performance and his loud bass voice for the character gained him a huge following.

[122] Avinash Ramachandran, writing for Cinema Express stated the possibilities of the connection, within the two films, referring to stash of drugs which had scorpion symbol (shown in Vikram's trailer), and in a scene where, Inspector Bejoy (Narain) while speaking to informer Ajhas Ahmed (Kanna Ravi), questions about "The Ghost", Suriya's undisclosed cameo before the film's release and several speculations.

[128] In an interview with Subha J Rao to Firstpost, Lokesh conveyed his interest on developing the film into a franchise, stating that he had an idea for both prequel as well as sequel, which depends on the recurring schedules of the cast members.

[132] In June 2022, Lokesh, in an interview with Baradwaj Rangan, revealed the backstory of Dilli, saying that he was a kabaddi player, and won several trophies in tournaments conducted when he was in prison.

[132][133] Later, in an interaction with fans through Twitter, he further explained about Anbu's return in Vikram, as he was knocked out and not dead, though he had stitch marks in his jaw, due to the injuries.

[135] Production of the film was expected to begin in the second quarter of 2022, but was delayed as Lokesh intended to resume the project after completing Leo and Rajinikanth's Coolie.

When Lokesh made the film, he was shocked to see that it was the same story, which the producer narrated to him and felt cheated, resulting him to file a petition at Kollam High Court, Kerala to stop the works on the sequel and its remake.