Migration is considered as one of the major risk factor for HIV/AIDS transmission. Inadequate knowledge and misconceptions about HIV/AIDS transmission are still the major challenges in developing countries. This study aimed to explore the knowledge and risk perceptions about HIV/AIDS among a sample of Nepalese migrants working in three Gulf countries. A cross-sectional study was performed among a sample of 408 adult Nepalese migrants who had a work experience of at least six months in one of the three Gulf countries, (Qatar, Saudi Arabia and United Arab Emirates). An interview-based questionnaire was used to obtain the information from these migrant workers. The respondents in this study were from different parts of Nepal and the majority were adult males, most frequently of age 26-35. More than half of the respondents were involved in construction related works. The majority of the respondents were aware that HIV virus is transmitted through sexual intercourse without using condoms and having sex with many people. The most prevalent misconceptions about HIV/AIDS transmission was that a person can get HIV/AIDS from a mosquito bite. More than a quarter of the respondents perceived that they were not at risk of being infected with HIV/AIDS due to their sexual activities. There is still a lack of adequate awareness and risk perceptions about HIV/AIDS among some of the Nepalese migrants. We can suggest to government of Nepal and employers to provide proper preventive health information regarding HIV/AIDS to migrant workers in both home and destination countries.