Diabetes mellitus (DM) is a systemic condition characterized by a deficient sugar metabolism, which affects the immune system and favors the development of yeasts. The aim of the present study was to perform biochemical, morphological, exoenzyme analyses of Candida species and the molecular identification (DNA) of C. albicans in patients with type II diabetes mellitus. The exoenzyme quantification was compared to non-diabetic patients as controls. Two hundred and seventy-four patients who make use of complete dentures were evaluated, 28 of whom had diabetes and erythematous oral candidiasis. Other thirty patients presented the same clinical feature but without diabetes. Samples were isolated for biochemical identification (auxonogram), morphological identification (production of germ tubes) and PCR molecular identification (DNA). The capability of the Candida samples in producing phospholipases and proteinases was also determined. The diabetic patients had a greater diversity of Candida species (Fischer's exact test, P = 0.04). The production of proteinases by C. albicans in patients with diabetes was greater than in the control group (unpaired "t" test P < 0.003). However, there was no difference between groups for phospholipase production (unpaired "t" test P > 0.05). It was concluded that patients with controlled DM exhibited systemic conditions predisposing C. albicans proteinase increased production.