Amarkkalam happens to be Ajith's milestone silver jubilee film. However, both the director and the actor weren't aware of this fact, when the film was conceived and when it went on floors.
Amarkalam is Ajith's second collaboration with director Saran and composer Bharadwaj after Kadhal Mannan. Saran had said that no other composer understood his requirements the way Bharadwaj does,
Amarkalam was bankrolled by Venkateswaralayam, which also produced Kadhal Mannan. The producer had met with losses after selling KM for lesser prices. So Ajith insisted on doing another film for them.
When Saran approached Shalini for the film's female lead, she refused saying that she wanted to quit cinema and pursue higher studies.
Saran then approached director Perarasu, who was close friends with Shalini's father, and narrated the script. Perarasu convinced Shalini to take up the role as it had equal scope as that of the Ajith
Amarkalam, interestingly, went on floors, without a script and just the title, during its announcement, as Ajith had promised a film for the production house.
Saran then developed a script revolving around a gangster, who loses his sight and in his recovery process, falls in love, and makes a lot of enemies. Ajith also okayed the script.
Later, after getting feedback that there were several movies with visually challenged characters made then, Saran changed the plot to the present storyline.
Jyotika was the first choice for the role of Mohana. But she couldn't accept the film because of scheduling conflicts.
Interestingly, when Shalini came on board, the song 'Sondha Kuralil paada' - which the actress ultimately sang - had already been recorded.
Saran, who noticed Shalini humming songs during the shot breaks, convinced her to attempt the song in her own voice. Vairamuthu reportedly altered a few lines after hearing about Shalini's involvement
The role of Tulasi Das was initially offered to Amitabh Bachchan who accepted before later pulling out of the film.
Raghuvaran, who was subsequently signed, brought his own body language and mannerisms to the character. Saran also reportedly rewrote a few scenes on Rahuvaran's suggestion.
Ajith's character is named Vasu, and in a scene where he understands love, he's seen watching the KB -Kamal Haasan classic, Ek Duje Ke Liye, where the protagonist was named Vasu as well.
Ajith's proposal to Shalini reportedly happened during their shooting in Srinivasa theatre.
Vasi's backstory - of a child shuttling between his separated parents - was inspired by actor Rahul Roy's childhood memories shared to Saran on the sets of KB's remake of Puthu Puthu Arthangal.
Ajith reportedly designed his own costumes and his accessories (chain, kaapu) for the film.
Ramesh Kanna's character was named Singampuli after the director-actor, who was an assistant director to Saran then.
While 'Megangal ennai thottu' was originally a poem of Vairamuthu, the 'breathless' song 'Satham illatha' originated from a poem where every line ended with vendum, and was later tweaked by Bharadwaj.
SPB, who had earlier sung a breathlessness part in Mannil indha Kadhal, was the first and the only choice for Satham Illadha Thanimai Ketten. The song was reportedly recorded at a stretch.
Maha ganapathy song was Raghava Lawrence's first screen appearance in Tamil, as Saran wanted him to appear on screen, impressed by his antics on the sets of a song for Cheran's Desiya Geetham.
Ajith and Saran reportedly travelled to Ooty after the latter developed a writer's block regarding the climax. It was eventually Ajith's idea to use Megangal ennai thottu in the climax.
Dubbing artist Sreeja Ravi voiced for Shalini in the film. She had earlier dubbed for the actress on several occasions.
Ajith and Shalini eventually got married in April 2000, an year after the film's release.
A digitally restored version of Amarkalam was released in theatres in May 2014, coinciding with the 43rd birthday of Ajith Kumar.
Ajith never smiles or dances throughout the movie's runtime. The only dance sequence in the film was conceived to be happening in a dream.