A series of studies designed to ascertain the relationship of gastric motility to hunger in man were carried out. The first, a 24-hour study of 3 subjects of normal weight, revealed no relationship between gastric or duodenal motility and reports of hunger or food intake. Four-hour studies of eight triads of neurotic obese, obese control and nonobese control subjects revealed a relationship between gastric motility and intensity of reports of hunger in a minority of subjects, distributed among all 3 groups. The neurotic obese subjects showed two distinctive characteristics--more frequent decrease in hunger over time, and impaired perception of individual gastric contractions. Perception of gastric contractions could be greatly improved by training. Such improvement, however, did not strengthen the relationship of gastric motility to hunger nor did it improve the ability to control food intake. Gastric motility appears to exercise a weak and inconstant subluence on hunger, and defects in perception of gastric motility do not seem to account for the disturbances in hunger or the control of food intake of neurotic obese or obese control persons.