The film marks the Hindi playback singing debut of Chopra, who provided her vocals for a song named "Chaoro" (a Meiteilon lullaby).

Kumar met Kom to ask her permission for the film, before her bronze medal victory at the 2012 Summer Olympics, which brought her recognition.

Chopra underwent extensive physical training for four months to attain a muscular physique and learned the sport and Kom's distinct boxing style.

Made on a budget of ₹38 crore (US$4.4 million), Mary Kom was released on 5 September 2014 to generally positive reviews with praise for Chopra's performance.

A young Mangte Chungeijang Kom, daughter of a rice farmer from Imphal, finds a boxing glove in the remains of an air crash in 1991 in Kangathei.

Kom challenges a local wrestler for money, in order to buy back a household cow, which the family had to sell off because of their financial troubles.

After watching her victorious 2002 Women's World Amateur Boxing Championships match on television, her father reconciles with Kom, and apologises to her for not understanding her passion for the sport.

[3] During his work as an art director on Sanjay Leela Bhansali's Saawariya (2007), Omung Kumar started writing two scripts simultaneously for his directorial debut.

[14] She was initially skeptical about the film due to the demanding nature of the character, which included training, muscle building, and learning the sport.

[4] The decision to cast Chopra proved controversial as some believed that an actress from Northeast India bearing Kom's likeness would be better suited for the role.

[4][5] Emphasizing Chopra's bankability and reach among the audiences Kumar remarked, "I not only needed a capable actress but also someone who can connect with millions of viewers".

[13][15] In an interview with Daily News and Analysis, Kom described Chopra as the best actress to play the role, adding that her body was well structured, like that of a boxer.

[7] In contrast, it took the casting directors Shruti Mahajan and Paragg Mehta several months of auditions to finalise the appropriate supporting actors for the film.

[5] In May 2013, a wide section of the media reported that Danny Denzongpa was approached to play Kom's coach Narjit Singh in the film.

[21] Though he did not get a chance to meet Kom, he used her videos to study her body language and prepare a workout plan for Chopra,[17] who started training in April 2013.

"[24] Chopra found Mary Kom a very special and personal film due to the inspiring story, adding that she pushed herself to do justice to the role.

[31] Kumar lost 12 kilogram to look the part, and followed a strict, grilled chicken and oil-free fish protein diet for three months.

[17] Miller roped in Christy Halbert, the United States's assistant coach at the London Olympics, to help choreograph the fight scenes.

Filming boxing scenes were difficult for Chopra as she was hurt several times; she says, "They are real boxers, and they don't know how to fake a punch, they had to really hit you.

[3] The soundtrack of the film consists of seven original songs composed by duo Shashi Suman and Shivamm Pathak, with lyrics by Prashant Ingole and Sandip Ssingh.

[52][53] It portrayed a muscular Chopra as Mary Kom in sports clothing, with her hair tied in a pony tail, punching a bag.

[66][67][68] On 27 August, a special screening was held for selected members of media, trade and critics, where 20 minutes of raw footage from the film was previewed, creating a positive buzz.

[80] However, unauthorised DVDs and VCDs flooded the state, with the DVD format in great demand as the only option for native people to watch the film.

[89][90] Subhash K. Jha awarded the film 5 stars out of 5, describing it as "a motivational masterpiece" and said "From first frame to last it grips your senses and irrigates the parched corridors of your heart like very few bio-pics in recent times.

[91] Rediff.com rated the film 4.5 out of 5, noting it as a victory for its protagonist Chopra, scriptwriter Saiwyn Quadras, and director Omung Kumar and wrote "Mary's story is delivered with a sincerity that makes it irresistible.

[95] Namrata Joshi from Outlook rated the film with 3 stars out of 4 and commented on the simple, unpretentious storyline that dramatised important events from the champion's life, complimenting Chopra's "sincere and earnest" performance.

"[100] Masand was impressed by Chopra's performance noting that the actress "transforms herself physically, and also skillfully conveys both the rage and vulnerability that the part required.

[101] However, Kamath felt that the film should be watched for Chopra who gave a "knockout" performance, writing "The spirited actress rises above the material and makes us invest in her.

"[102] Shubhra Gupta from The Indian Express gave a rating of 2.5, noting that the "Film gets bloated by extraneous songs", and criticised the product placements calling them a "distraction from the story.

"[103] The India Today reviewer, Rohit Khilnani, criticised Kumar's direction and wrote "The story is predictable from the word go and there are absolutely no surprise elements.