Purpose To assess the Meibomian glands, ocular surface and tear function in patients with type 2 diabetes, and study the correlation between these conditions. Methods Prospective study of 76 males, 37 with type 2 diabetes with an average of duration between 7 ± 5 years, and 36 males from control group. After completing an ocular surface disease index (OSDI) questionnaire, the non-invasive tear film break-up time (NIBUT) and the tear lipid layer pattern was performed using interferometry system and tear meniscus height/TMH. Ocular surface was studied with lissamine green staining and morphology of the glands with evaluation of Marx's line (lid margin abnormalities); meibomian secretion was expressed and was also assessed the quality. The results were analyzed using the statistical Kruskal-Wallis and Mann-Whitney, and correlations by Spearman Rho. Results The mean age was 59 ± 8 years; 71% of participants presented MGD (76% diabetics and 67% controls). OSDI were significantly higher (p = 0.01) in the diabetic group. A positive correlation was found between glycemia and symptoms (p = 0.0005) and strong correlation between Hb1Ac and OSDI in MGD. NIBUT was lower in the control group (2.47 ± 1.2 s) than for the diabetic group (2.9 ± 1.2 s), with a significant inverse correlation (52.22%) with MG inflammation. Conclusions MGD in type 2 diabetic patients is more severe compared with nondiabetic patients. Longer duration of diabetes is associated with major symptoms and changes in MG. Diabetic group showed major changes in lids and tear function, accounting for evaporative dry eye and presenting a high degree of correlation with MG inflammation and obstruction. Keywords Meibomian gland dysfunction Diabetes Dry eye NIBUT Marx's line