In sub-Saharan Africa, the prevalence of stigma-related abuse and violence among men who have sex with men (MSM) and its potential impact on the HIV/AIDS epidemic is unknown. This study estimated the prevalence and source of violence and abuse among a sample of MSM in Tanzania and characterized the association between levels of violence and sexual and mental health variables. Data were taken from a larger study of 200 MSM in Tanzania. Frequency tabulations, bivariate analysis, and logistic regression were performed to describe the prevalence and source of abuse and to determine the association between levels of violence and sexual demographics and mental health variables. The MSM sample for this study was young (median age 23), somewhat educated with the majority having attained secondary school (80%) and mostly employed (60%). Verbal (48.5%) and moral (32.5%) abuses were the most predominant types of abuse among the sample and were mostly from people in the street and neighbors. Sexual abuse (30%) was mostly from partners, and physical violence (29.5%) was largely from people in the street. Participants in the high-violence level group had a significantly greater number of sexual partners, depression scores, and internalized homonegativity (IH) scores. IH predicted HIV infection and verbal abuse predicted IH.There is a need for an increased awareness of violence and abuse faced by MSM in Tanzania, as well as effective programs to specifically target the issue of violence among MSM, and its implication for mental health and for risky sexual behaviors and HIV transmission.