Objective It is thought that environmental agents, especially the diet, play an important role in the processes of gastric cancer. The study was designed to investigate the relationship between dietary factors and the risk of gastric cancer in residents of islands so as to offer the evidence for effective measures of prevention and control. Methods A frequency matched design of case control study was used. 103 cases of gastric cancer newly diagnosed in 2001 and 133 controls were randomly selected among the residents of islands. And dietary factors were further investigated. Adjusted odds ratios (OR) and 95% confidence intervals (CI) of dietary factors on the processes of gastric cancer were estimated using unconditional logistic regression models. Results After the correction of the effects of some non diet factors, increased risks of gastric cancer were associated with hot diet (OR=1.48,95%CI:1.03 2.14) and pickled food (OR=2.63,95%CI:1.74 3.98). An inversed association with the risk of gastric cancer was seen in sauting (OR=0.33,95%CI:0.13 0.83 ), food eaten at regular time (OR=0.29,95%CI:0.19 0.44), allium vegetables (OR=0.43,95%CI:0.22 0.82) and carrot (OR=0.10,95%CI:0.02 0.41). Furthermore, PARc% of hot diet and pickled food were 11.8% and 57.8% respectively, which suggested that the carcinogenic effect of hot diet and pickled food on stomach in the population reached about 70% after the correction of the effect of other factors.Conclusions Pickled food and hot diet as the habits of residents in Zhoushan islands are important risk factors for gastric cancer, while decreased risk effect is found in sauting food, having regular dietary time and frequently eating allium vegetables and carrot.