Belize has the highest rates of HIV infection in Central America and is experiencing a generalized epidemic. The Garífuna, a minority ethnic population, is at risk for HIV. This study uses survey data from Garífuna men and women to examine the frequency of multiple partnerships as well as sociodemographic characteristics and behavioral constructs correlated with having multiple partners. A high proportion of respondents reported having multiple partners, but rates were significantly higher for men, and men had a higher mean number of partners than women. A high proportion of respondents reported having a sexually transmitted infection (STI) in the last year, with more men reporting a history of STIs than women. Regression results show the importance of improving men and women's perceived susceptibility for HIV and encouraging them to know their HIV status. Reinforcing a social norm for partner reduction would also benefit men. Study findings support the need for HIV counseling and testing in Garí-funa communities as well as STI prevention, diagnosis and treatment. This study demonstrates that reducing multiple partnerships among Garífuna men and women is critical for reducing the spread of HIV in Belize.