The aim of the study was to evaluate the relationship between smoking status and the incidence of microvascular complications in patients with type 1 diabetes (DM1), treated with intensive functional insulin therapy (IFIT) from the onset of the disease.81 participants (51 men, 30 women) of Poznan Prospective Study (PoProStu) with mean age of 34.0±6.4years were included in this analysis. Patients were observed for 10.0±1.5years. Evaluation of microvascular complications of diabetes, such as retinopathy, diabetic kidney disease and neuropathy was performed. Patients were divided into two groups depending on the smoking status: smokers and non-smokers.In the group of smokers (n=36) in comparison with patients who had never smoked (n=45) any microangiopathy (58.3% vs 33.3%, p=0.02), retinopathy (44.4% vs 20%, p=0.02), diabetic kidney disease (47.2% vs 24.4%, p=0.03) and neuropathy (25% vs 4.4%, p=0.02) were found more often. A significant relationship, adjusted for age, sex, duration of diabetes, presence of hypertension and HbA1c between smoking and neuropathy and retinopathy was revealed [OR 10.16 (95%CI 1.59–64.95); p=0.01 and OR 3.50 (95%CI 1.01–12.12); p=0.04, respectively].The results show that in patients with DM1, there is a strong relationship between smoking and the diabetic microvascular complications, especially with neuropathy, despite treatment from the initial diagnosis with intensive insulin therapy.