Among 6321 patients who had undergone X-ray examination of the colon 4.7 per cent proved to have osteoarthritis of the hip. A mild osteoarthritis was found to be equally common in both sexes, but in all age groups above 60 severe osteoarthritis of the hip was twice a common in women as in men. Osteoarthritis setting in at an early age was secondary to other hip conditions. In 50 per cent of the patients the arthritis was located laterally and in 24 per cent medially. The medially located osteoarthritis was less troublesome than the lateral. According to the present study, only half the patients who exhibit radiological evidence of osteoarthritis of the hip actually need treatment. In keeping with the fact that the osteoarthritis was more severe radiologically in women than in the men, the women were also more severely affected by the condition. They more often had to apply for disablement pension they had more severe pain, and they were more handicapped in activities of daily living.