Background/Aim. Diabetes mellitus (DM) is considered to be an epidemic, chronic and progressive disease. The treatment of DM reqiures substantial effort from both the diabetes treatment team and a patient. Patient education is one of the treatment elements. The most efficacious form and content of education has not yet been established. However, every DM education must include introduction to a substantial number of facts about diabetes. The aim of our study was to estimate the levels of DM knowledge and glycemic control in Serbian patients with DM type 2 as well as to estimate the effects of education using printed material on the levels of glycemic control and knowledge about DM. Also, the effects of education on glycemic control and the level of knowledge in differently treated patients were estimated. Methods. The patients with DM type 2 (n = 364), aged 40 to 65 years, from three regional health centers, were randomized for the study. After informed consent, patients filled out the questionnaire, and were checked for HbA1c and fasting blood glucose. Finally, booklet „Healthy lifestyle with diabetes mellitus type 2“ was given to them. The same procedure was repeated after 3, 6 and 18 months. Results. There was a significant improvement in HbA1c levels after 3 months (8.00 ± 1.66% vs 9.06 ± 2.23%, p < 0.01) and after 6 months (7.67 ± 1.75% vs 9.06 ± 2.23%, p < 0.01). There was no further improvement in HbA1c levels after 18 months (7.88 ± 1.46% vs 7.67 ± 1.75%, p > 0.05). There was a significant improvement in the average test score (percent of correct answers per test sheet) after three monts (64.6% vs 55.6%, p < 0.01). There were no further statistically significant changes in the general level of DM knowledge after 6 months (65.0 ± 32.5% vs 64.5 ± 33.7%, p > 0.05 ) and after 18 months ( 64.8 ± 32.7 vs 64.5 ± 33.7%, p > 0.05). There was a significant difference in educational intervention response in DM type 2 patients on different therapeutic regimens. Conclusion. Education with printed material led to improvement in glycemic control and level of DM knowledge in our patients. Education with printed material may be a useful adjunct to DM treatment and should be structured according to the treatment modality.