It is difficult to assess the proportion of individuals who experience an acute seroconversion illness after infection with HIV-1. We found that five out of 27 recent HIV-1 seroconverters (18.5%) in a population-based cohort in rural Uganda and four out of 22 HIV-negative controls (18.2%) reported a flu-like illness. More symptoms were reported by seroconverters, but the duration of illness was similar in both groups. We found no association between symptoms and infection with HIV-1 subtype A or D.