Diabetes develops in more than half of the patients with chronic alcoholic pancreatitis (CAP), mostly due to increasing insulin deficiency. In this regard CAP-related diabetes (CAP-DM) is similar to the type 1 diabetes. Data on microvascular complications in CAP-DM are scarce. The aim of the study was the analysis of microvascular complications frequency in relation to metabolic control in comparison with type 1 diabetes mellitus. The study subjects were 50 patients divided into two groups: group 1-25 patients with CAP-DM (15 men, 10 women, mean age 44.6 +/- 8.4 yrs, duration of diabetes 3.7 +/- 2.1 yrs, body mass index (BMI) 22.4 +/- 2.9 kg/m2, duration of CAP 7.0 +/- 3.5 years), and group 2-25 well-matched type 1 diabetes patients (14 men, 11 women, mean age 42.3 +/- 7.6 yrs, duration of diabetes 4.1 +/- 2.8 yrs, BMI 24.0 +/- +/- 2.5 kg/m2). CAP was diagnosed on the basis of clinical examination, ultrasound and computed tomography scans, and in some cases upon the results of endoscopic retrograde pancreatography. Fasting plasma glucose, glycated hemoglobin (HbA1c), total serum cholesterol, triglycerides, urea and creatinine concentrations were measured. Fundoscopy was performed in all the subjects, in addition fluorescein examination was conducted in 15 and 18 patients from groups 1 as 2 respectively. Fasting plasma glucose, HbA1c level and insulin requirement were significantly lower in CAP-DM patients than in type 1 diabetes subjects (133 +/- 48 vs 174 +/- 59 mg/dl, p < 0.01; 8.3 +/- 2.0 vs 9.8 +/- 1.1%, p < 0.01; 36 +/- 15 vs 57 +/- 11 IU/day, p < 0.001 respectively). However, the prevalence of background retinopathy (group 1-13/25, group 2-11/25), and microalbuminuria (group 1-14/25, group 2-13/25) was similar in both groups. No statistically significant differences were found between CAP-DM and type 1 diabetic patients in regard to blood lipids, triglycerides, urea and creatinine concentrations. We conclude that microvascular complications may be encountered in pancreatic diabetes as often as in type 1 diabetes. Therefore this particular type of secondary diabetes should be regarded by no means as a "milder" type of the disease.