Oral candidiasis represents a serious problem for children with cancer. The mortality rate of this infection has increased due to fungal septicemia, associated with a primary buccal infection. Objective: Identify the Candida spp. in buccal lesions of patients with cancer, establish the predominant species and correlate them to age and sex of the patient, clinical presentation, type of neoplasic disease and cytostatic therapy received. Study design: 62 patients, between 0-16 years, were investigated in a cross sectional study. Sample inclusion criteria: Patients with malignant neoplasic disease that were receiving cytostatic treatment and had suspicious lesions of oral candidiasis. Patients with antifungal therapy, active caries, calculus or intraoral appliances were excluded. A clinical evaluation was carried out. The lesion sample was taken and studied by direct exam and culture in CHROMagar-Candida and Sabouraud-Dextrose Agar with chloramphenicol. The identification of the isolated yeast was done by the filamentation test, carbohydrate fermentation and assimilation. Results: Most of the cases (69.35%) were positive to oral candidiasis, C. albicans was the most frequent species found, followed by C. parapsilosis (14.89%), C. tropicalis (12.77%), C. krusei (4.26%), C. glabrata (2.13%) and C. lusitaniae (2.13 %). In some cases more than one specie were isolated (9.30%). The most frequent location of the lesion was in the tongue (72.70%). The pseudomembranous candidiasis was the most frequent clinical presentation found (78.71%). There were not significant statistically differences with regard to sex and age of the patient, type of neoplasic disease and cytostatic agent received. Conclusion: The results suggest that oral candidiasis is a frequent complication in the pediatric oncological population, being C. albicans the main etiological agent, however, there is an important participation of other Candida species.