The number of notified syphilis cases in Tokyo has more than doubled in recent years. The number of reported primary and secondary syphilis cases increased from 108 cases (0.8 per 100,000 population) in 2007 to 245 cases in 2013 (1.9 per 100,000 population). During this period, the majority of cases was male (905/1,024), and the recent increase among primary and secondary syphilis cases was attributed to the increase among males (90/108 [83%] cases in 2007 to 218/245 [89%] cases in 2013); men aged 20–49 years contributed most to the increase, with those aged 30–34 years having the highest notification rate in 2013. Male-to-male transmission was the primary route of infection reported, and men who have sex with men (MSM) accounted for nearly 80% of male cases in 2013. Syphilis appears to be reemerging in Tokyo, and reducing the risk of acquiring syphilis among MSM aged 20–49 years should be a public health priority in Tokyo.