Abstract: Objective To understand the underreporting of sexual transmitted diseases (STDs) in Xinjiang and provide evidence for the prevention and control of STDs and AIDS. Methods Three surveys of STDs underreporting were conducted in medical institutions at all levels in Urumqi respectively from 2009 to 2011. Results From 2009 to 2011,54, 58 and 60 medical institutions in Urumqi were surveyed. The underreporting rate of STDs was 2.93% (21/716), 4.84% (31/641) and 3.70% (26/702) respectively. Conclusion It is essential to strengthen the supervision of the case reporting, conduct standardized management, establish reward and punishment system, improve medical staffs ability and promote data informatization to improve the reporting quality of STDs.