Most hematogenous candidiasis originates from endogeneous host. ora. Fungal. ora of gastrointestinal system are important source of infection especially in immunosupressed patients. The purpose of this study was to investigate the fecal fungal. ora of pediatric patients with hematologic malignancy or disorders and to compare the results with healthy volunteers. For this purpose, fungal etiological agents were investigated retrospectively in stool samples of 80 patients followed in Bone marrow transplantation and Hematology Oncology units. The diagnosis of patients were as follows: 26 acute myelogeneous leukemia, 19 acute lymphocytic leukemia, 5 lymphoma, 3 chronic myelogeneous leukemia, 2 solid tumor, 4 neuroblastoma and 21 hematologic disorders. In patients, totally 102 fungal growth was detected and 42 (41.2%) C. albicans and 51 (50%) non-albicans Candida species and 9 (8.8%) yeast other than Candida and mould was isolated. The results were compared prospectively with growth in stool samples of 61 healthy children. C. albicans was detected in 16 (43.2%) and non-albicans Candida species in 15 (40.5%) and yeasts other than Candida and mould in 6 (16.2%) of 37 fungal growth in controls. Non-albicans Candida species growth was found significantly higher and C. glabrata was more prevelant in patients than in controls (p < 0.001).