To inform efforts to curb HIV in Botswana, we describe sexual concurrency and related norms and behaviors among a sample of 807 Batswana age 15-49 years who participated in a 2003 population-based survey. Of 546 sexually active respondents, 23% reported ever having a concurrent sexual partnership with any of the last three partners from the last 12 months. Multivariate analysis found that men and youth (age <25 years), and non-religious people were more likely than their respective counterparts to report concurrency. Respondents reporting concurrency were more likely than those not, to have norms that support multiple partnerships and report low self-efficacy to be faithful to one partner. However, a majority of both groups reported believing that fidelity is important and that they would be looked down upon by family and friends if discovered to have multiple partnerships. The findings suggest that concurrency in Botswana is not uncommon, and yet may not be generally acceptable.