In a large population-based survey, 1947 Type 2 diabetic subjects aged 40 yr and over were identified, with high ascertainment (91%). Age-specific prevalence increased from 2.48% in the age group 40-64 to 5.62% in the age group > or = 65 yr; 35% of subjects were 65 yr and over at the onset of the disease. Elderly diabetic subjects showed a significantly (p or = 65 yr. Poor metabolic control was more commonly seen in those attending the diabetic clinic. HBA1c measurement was available in 32.0% of the elderly attending the diabetic clinic and in only 10.7% of those in the care of GPs. Fundal examination was available in 48.2% and in 36.5%, respectively, of diabetic subjects in the age groups 40-64 > or = 65 yr, without differences between those attending and those not attending the diabetic clinic.(ABSTRACT TRUNCATED AT 250 WORDS)