In Suleimania Children's Hospital, Riyadh, Saudi Arabia, 110 diabetic children were diagnosed and followed over a 5‐year period (1985–1989). Seventy‐five percent (82/110) were of Saudi origin and 54% (59/110) female. Their parents were often related, 31% (34/110) being first degree cousins, and 12% (13/110) second degree cousins. First degree family history was positive for Type 1 diabetes in 28% (31/110). Among these cases, siblings accounted for 26%, fathers 2%. and mothers none. Family history was also positive for Type 2 diabetes in 35% (38/110) and for both Type 1 diabetes and Type 2 diabetes in 14% (15/110). Mean age at onset was 5.9 years (7 months to 12 years). Thirty percent (33/110) of the patients were under 3 years of age on admission. The most common clinical presentation was diabetic ketoacidosis, seen in 67% of the patients (74/110). 1991 Diabetes UK