Introduction With a transient and isolated lifestyle, little knowledge about sexually transmitted infections (STIs) or HIV/AIDS along with a tendency toward risky sexual behaviour, the migrants are always at higher risk for HIV and STIs. The present study aims to explore the knowledge and awareness about STI/HIV and the misconceptions among the undocumented Bangladeshi migrants in Kolkata, India.

Methods Bivariate and multivariate techniques were used for analysing the data which was collected in the year 2016 from 400 undocumented cross border Bangladeshi migrants residing in Kolkata, India using respondent driven sampling.

Results Only 18 percent of the migrants have heard about STIs and around three-fifths about HIV/AIDS. The main source of information about STI was health workers and doctors while for HIV/AIDS it was friends/relatives. Very few migrants reported that condoms can prevent STIs as compared to 80% reporting condoms as well as sex with one uninfected partner can prevent HIV/AIDS. More females than males recognised the actual symptoms of STIs. Around two-fifths migrants had the misconception that only bad people get STIs and by presence of STI will reflect on appearance. Half migrants reported that taking antibiotic from chemist will cure STI. One tenth of the migrants had misconception and agreed that it can be transmitted by mosquito bite and sharing food/water with HIV patient. A considerable proportion also reported that people can get HIV by hugging someone with AIDS.Binary logistic regression shows that aged migrants (40+), those who have mass media exposure, HIV/AIDS awareness and condom knowledge are more likely (p<0.001) to know about STIs. The males are 85% less likely to know about STIs (p<0.001). While, educated migrants and those having STI knowledge are more likely(p<0.001) to be aware of HIV/AIDS.

Conclusion The lack of STI awareness, misconceptions and gender gap in STI and HIV knowledge among the undocumented migrants calls for gender specific interventions to reduce cross border migrant’s elevated risk of contacting STIs/HIV.