Sunita hails from Sunam, Punjab and is best known for her performance at the 2002 Asian games, where she won a gold medal in the 1500 m and a bronze medal in the 5000 m races.

Sunita has spoken out about the need for better facilities in order to motivate athletes. She was also working as an Superintendent of Police in Pathankot, Punjab.

Sunita Rani was hit with controversy about her performance at the 2002 Asian games, where she won a gold medal in the 1500m and a bronze medal in 5000m, after she tested positive for nandrolone, a banned substance that aids recovery, strength and endurance, in the dope tests. Both her medals were revoked. However, the Indian Olympic Association fought to prove that the doping tests had major procedural irregularities, and that the results were not valid. Rani has categorically maintained that she had not taken any banned substances. She had also cleared the dope test in Delhi, on the eve of the Indian team's departure to Busan.

The Olympic Council of Asia later officially admitted that there had been discrepancies in her dope test. On January 3, 2003, the International Association of Athletics Federations officially cleared her off her doping charges, and reinstated her medals. The Amateur Athletic Federation of India held a 'Restoration of Medals' ceremony on February 4, 2003, to officially return her medals to her.