Hereditary spherocytosis (HS) is the most frequent cause of congenital hemolytic anemia. It is an autosomal dominant genetic disorder characterized by cell membrane abnormalities, specifically in red blood cells. Although the association between benign, borderline and malignant tumors and HS is not clear, various tumors such as splenoma, adrenal myolipoma, pancreatic schwannoma, ganglioneuroma, extramedullary hematopoiesis, myeloproliferative disorders, multiple myeloma, B-cell lymphoma and acute lymphoblastic leukemia have been presented in case reports concerning HS patients. Here we describe a 6-year-old boy with HS who presented with a mass in the left kidney. Tru-cut biopsy revealed Wilms' tumor (WT). To the best of our knowledge, this is the first case of WT associated with HS to be reported in the literature.