Although the HIV epidemic is generalized in West Africa, some population groups such as men who have sex with men (MSM), especially those engaged in transactional sex (TS), are thought to be particularly more vulnerable to HIV than others. However, few data are available to help identify their health-related needs with a view to implementing targeted prevention interventions. To fill this knowledge gap, we aimed to characterize MSM reporting TS (MSM-TS) and to identify factors associated with their sexual practices using data from the prospective cohort study CohMSM, which was conducted in Burkina Faso, Cote d'Ivoire, Mali and Togo. Three stigmatization sub-scores were constructed (experienced, perceived and internalized). The generalized e...