In the last decade, three randomized controlled trials in Kenya, South Africa, and Uganda have shown that medical male circumcision (MMC) reduces the sexual transmission of HIV from women to men. Objectives of this assessment were to measure acceptability of adult MMC and circumcision of children to inform policies regarding whether and how to promote MMC as an HIV prevention strategy. This mixed-method study, conducted across four Ugandan districts, included a two-stage household survey of 833 adult males and 842 adult females, focus group discussions, and a health provider survey. Respondents' acceptability of MMC was positive and substantial after being informed about the results of recent randomized trials. In uncircumcised men, between 40% and 62% across the districts would consider getting circumcised. Across the four districts between 60% and 86% of fathers and 49% and 95% of mothers were supportive of MMC for sons. Widespread support exists among men and women in this study for promoting MMC as part of Uganda's current 'ABC + ' HIV prevention strategy.