In 1955-66, 1,085 Chinese with diabetes came under the care of the University Department of Medicine. In 1966, the crude death rate from diabetes in Hong Kong was 3.2 per 100,000 and this is, for reasons advanced, thought to be lower than the actual death rate. It is concluded that diabetes is certainly not the rarity among the Chinese that it has been reported to be. Diabetes among the Chinese was found to differ in a few particulars from diabetes in the West. Diagnosis before the age of forty was slightly less common: 20 as against 25 per cent. The majority of patients of both sexes were either of normal weight or were underweight and, in some, active pulmonary tuberculosis, which had a prevalence of twenty times that encountered in the general population, played a part. Both the number overweight and its degree were very much less than among diabetic patients in the West. There were two striking additional differences in that there was a very low prevalence of myocardial ischemia, and of occlusive peripheral vascular disorder (4.7 and 1.4 per cent respectively). Nevertheless, the prevalence of each was much higher among diabetic than among nondiabetic admissions to hospital. It is concluded that the low rates of these two conditions reflect their low rates in the population as a whole and do not infer a fundamental difference in the diabetes per se. Dupuytren's contracture was not encountered, but this is not surprising for the diathesis does not seem to occur among the Chinese. There was a higher prevalence of “frozen shoulder” and of tenosynovitis leading to “trigger finger” in diabetics than in nondiabetics and these complications, as far as we are aware, have not been reported previously. In other ways the characteristics of the Chinese diabetic patient in Hong Kong resembled his counterpart in the West. The over-all sex incidence and the preponderance of women after the age of forty were as in the West. Severe diabetic ketosis was encountered in 6.0 per cent. Hypertension occurred equally commonly, and the eye, renal and neurological complications differed neither in prevalence nor severity from those seen in diabetic populations in the West. For the first time retinitis proliferans, which occurred in eleven of 156 patients with retinopathy, is reported in Chinese diabetics as is also the occurrence of painless parotid enlargement in six patients, a complication which would appear to be a rarity in the West. It is concluded that diabetes mellitus, certainly among the Chinese in Hong Kong and, perhaps, elsewhere, is not the mild disease it has been claimed to be. The concept, that climate was responsible for the high prevalence and severity of diabetes in temperate regions and for a low frequency of a mild form of diabetes in tropical and subtropical regions is not borne out by the present study.