To evaluate a combined effect of gastric cancer family history (GCFH) and selected living habits on the subsite-specific of gastric cancer, a hospital-based case-referent study was conducted in Tokai area of Japan. The study subjects were 850 newly diagnosed gastric cancer (GC) patients and 28,619 cancer-free first-visit outpatients. Odds ratios (ORs) of all subsites of GC in subjects with both GCFH and habitual smoking were significantly higher (OR = 4.22) compared with those with merely GCFH (OR = 1.81) or habitual smoking (OR = 2.83). When positive GCFH subjects frequently consumed raw vegetable, the risk of GC decreased in cardia (OR = 0.68), antrum (OR = 0.43) and all subsites (OR = 0.74). Our findings provided evidence that GCFH and habitual smoking increased the risk of GC with family history, while frequent intake of raw vegetable decreased the risk and it was modified by other environmental factors.