We analyzed data on reported mode of transmission in case reports of HIV-infections among men in
Ukraine. The number of men who were reported to have acquired HIV through heterosexual transmission increased substantially in 2006–2011. However, we estimate that up to 40 % of reported cases of heterosexual transmission among men may actually represent misclassified men who have sex with men or persons who inject drugs. These findings indicate a need to improve the quality of data on
reported mode of HIV transmission. Accurate information has important public health implications in planning prevention and treatment services.