OBJECTIVES: To investigate smoking cessation behaviors in Japanese current smokers (CS) and former smokers (FS). METHODS: An online survey of Japanese men and women ≥20 years of age who were CS or FS was conducted. CS were those who smoked any number of cigarettes at the time of the survey (24–27 June 2013); FS were those who had smoked any number of cigarettes in the past but did not consider themselves smokers at the time of the survey. Clinical and socio-demographic characteristics (age, gender, level of education, and level of nicotine dependence [Fagerström Test for Nicotine Dependence]) as well as smoking and smoking cessation history, were assessed through a web-based questionnaire.  We set primary outcome measures as the number of past quit attempts and the time to relapse (duration of smoking abstinence). Secondary outcome measures included methods used to achieve smoking cessation, and reasons for wanting to quit.  RESULTS: A total of 1261 eligible Japanese subjects were included in the survey (CS, n = 631; FS, n = 630). Mean age and gender distribution were broadly similar between the groups. Nearly half (45.6%) of CS had never attempted to quit smoking. Of those who had attempted to quit smoking, one single quit attempt was the most common for both CS and FS (19.0 vs. 39.0%). The estimated median time to relapse was 105 days (FS and CS combined). Unaided smoking cessation was the most common method both for CS and FS (78.2 vs. 63.4%). CONCLUSIONS: Our observations reveal the actual smoking cessation behaviors in a Japanese population, and could be combined with other data in economic evaluation models of smoking cessation interventions in Japan to identify appropriate measures to reduce the prevalence of smoking.