A systematic review was conducted to summarize and appraise the eHealth interventions addressing HIV/STI prevention among men who have sex with men (MSM), and characterize features of successful eHealth interventions. Fifty-five articles (17 pilots and 38 full efficacy trials) were included with the predominance of web-based interventions in the United Statesbased settings. Intervention modalities include web-based, short message service (SMS)/text messges/email reminder, online video-based, computer-assisted, multimedia-based, social network, live chat and chat room, virtual simulation intervention, and smartphone applications. Forty-nine eHealth interventions achieved a short-term behaviour change among participants. Four studies were conducted with 12-month follow-ups; and only one of them could maintain the behaviour change over this longer time period which could be due to the lack of booster interventions. Our study suggests that eHealth interventions can achieve short term behaviour change among MSM, however limited interventions could maintain behaviour change over 12 months. Further eHealth intervention strategies to promote HIV prevention among MSM should be conducted and rigorously evaluated.