Purpose: We observed the frequencies of microvascular complications and their related factors in patients with type 1 diabetes. Methods: Two hundred seventy one patients (111 males and 160 females, mean age 21.9 ± 5.8 years) with type 1 diabetes were included. Subjects were all at least 10 years old and had diabetes for at least two years. Three types of microvascular complications (diabetic nephropathy, retinopathy, and neuropathy) were evaluated, and their frequen cies and risk factors were analyzed. Results: The overall prevalence of microvascular disease was 83/271 (30.6%). Microalbu minuria had developed in 39 patients (14.4%), persistent microalbuminuria in 31 patients (11.4%), and proteinuria in 12 (4.4%). Diabetic retinopathy had developed in 35 patients (12.9%) and neuropathy in 39 patients (13.7%). The mean HbA1c for 10 years was significantly higher in the patients with microvascular complications (10.5 ± 2.8% vs. 8.4 ± 1.4%). The rate of intensive management in the noncomplication group was higher than in the microvascular complication group. The incidence of microalbuminuria was greater in males than females, but there were no gender differences in either diabetic retinopathy or neuropathy. Puberty and the duration of diabetes may be associated with microvascular complications. Conclusion: The incidence of microvascular complications in type 1 diabetes is declining. Sex, puberty, and the duration of diabetes as well as prolonged hypergly cemia are all related to microvascular complications. Therefore, intensive insulin mana gement and regular screening for microvascular complications should be performed in patients who have either entered into puberty or have had diabetes for more than 5 years.