Background Unprotected anal sex is associated with the highest risk of transmission of sexually transmitted infections (STIs) and human immunodeficiency virus (HIV). This is due to the delicate nature of the rectal mucosa and anal sphincter. Any from of trauma to rectal mucosa in the receptive partner provides opportunity for the transmission of HIV/STI. The risk is more if the receptive partner is female. The aim of this study was to observe the prevalence and associated factors associated with anal sex practises among female sex workers (FSWs) in the western part of Assam, India.

Methods All total 64 FSWs were interviewed with a questionnaire to collect information regarding the respondents’ knowledge and their practises related to anal sex as well as related socioeconomic factors.

Results 61 FSWs (95.3%) reported having ever engaged in anal sex. 75% FSWs (48 cases) were aware of HIV/AIDS. Only 10.9% FSWs (seven cases) were aware of the fact that unprotected anal sex has the higher risk of HIV transmission.

Conclusion This study showed the practise of anal sex is quite common among FSWs, but their perception of HIV transmission risk associated with anal sex is very low. This is an alarming situation. It is important for HIV prevention programmes to focus not only on vaginal sex but also on risk associated with anal sex.