PurposeThis study investigated the prevalence of smoking, drinking, and physical inactivity and the associated factors of these behaviors in gastric cancer survivors.Materials and MethodsThe baseline data from the nationwide cohort study was used. Four hundred thirty-seven gastric cancer survivors who survived ≥ 2 years from diagnosis and reported completion of treatment were matched with 4,370 controls according to age, sex, education, and household income.ResultsThe prevalence rates of current smoking and drinking among gastric cancer survivors were 8.7% and 38.3%, which were significantly lower than those among matched controls (p ≤ 0.001), but the prevalence rates of physical inactivity were not significantly different (55.8% vs. 59.9%, p=0.248). In gastric cancer survivors, ≥ 5 years since cancer diagnosis and current drinking contributed to more current smoking; otherwise, age increment and femalewere associatedwith lower current smoking. Thosewith household income ≥ $2,000 and current smokers were more likely to drink and female showed less drinking. Female, currently employed state, and self-rated health status were associated with more physical inactivity.ConclusionAlthough gastric cancer survivors showed better health behaviors than controls, suggesting that the diagnosis of cancer may motivate individuals towards healthy behaviors, their current prevalence rates of smoking and drinking were still high, and more than 50% of them were physically inactive. Tailored interventions to improve their health behaviors considering associated factors for the gastric cancer survivors are necessary.