The degree of a patient's emotional maturity and the supportive value of his home, working, and recreational environments were scored by psychosociological methods preoperatively in a group of 47 patients who were intensively investigated with regard to the dumping syndrome. After surgery, the result of the operation was independently assessed as a success or a failure. At that time, a careful review was performed of each patient's clinical state, with particular reference to postgastrectomy syndromes. Positive associations were found between surgical failure and emotional instability, recorded by an Eysenck personality inventory, and scored social deprivation. Failure also correlated with the sum of the postgastrectomy syndromes and with recurrent pain, heartburn, episodic diarrhoea, and psychiatric illness in particular. The dumping syndrome itself did not contribute to failure.