An analysis of the last 20,000 newly diagnosed diabetic patients consecutively registered from 1 January 1981 to 6 June 1991 in the Bucharest Registry of Diabetes showed the following: (1) primary insulin-dependence (Type 1 diabetes) was encountered in only 7% of cases: the rest were Type 2 diabetic patients (8745:43.7% treated with diet alone and 9856:49.3% treated with diet and oral drugs); (2) low body weight (BMI < 25) was encountered in 81.7% of patients in the age group 0-20 years, while obesity (BMI > 27) was encountered in 75.7% of cases in the age group 41-65 years; (3) the overall annual incidence of the Type 1 diabetes for all ages was 5.7/100,000, lowest (1.3/100,000) in the age group 0-4 years and the highest 10.1/100,000) in the age group 65-69 years; (4) the overall annual incidence for the Type 2 diabetes was 76.3/100,000, the lowest (2.4/100,000) in the age group 20-24 years and the highest (261.4/100,000) in the age group 60-64 years. Studying the relationship between the onset of Type 1 diabetes mellitus and age, we did not observe the previously reported strong relationship, so that the distribution of Type 1 diabetes can be considered relatively uniform, with the exception of extreme ages. In conclusion, each year, about 1 in 1000 inhabitants of Bucharest are registered as having diabetes, the majority (93%) had type 2 and only 7% had Type 1 diabetes, one of the lowest incidence rates in Europe.