Forty colorectal cancer patients, 14 gastric cancer patients, and 10 normal controls were tested with the Social Readjustment Rating Scale. The gastric cancer patients had a significantly higher amount of life change (p less than 0.05) in the 2-year period preceding the onset of the first symptoms of their illness. Moreover, there was a significant (p less than 0.01) negative correlation between amount of life change and age at onset of symptoms in gastric cancer, but not in colorectal cancer. There was also no correlation between age and life change in the normal controls. These findings suggest that emotional stress may be a predisposing factor in gastric cancer.