Non-Hodgkin lymphoma (NHL) accounts for approximately 60% of all lymphomas in children and adolescents. It represents 8-10% of all malignancies in children aged between 5 and 19 years. Primary rectal lymphoma in childhood is extremely rare. This report focuses on the importance of considering the possibility of malignancy in rectal polyps. We report a 5-year-old girl with fresh rectal bleeding who was admitted in our clinic. In physical exam, we found a single pedicled polyp on the posterior wall of the rectum. Surgical removal under general anesthesia involved polyp and its pedicle. Dimensions of the extirpation material were 1.5 x 1.0 x 0.8 cm. Histopathological examination and immunohistochemistry study of the polyp revealed a high-grade B-cell lymphoma (Burkitt lymphoma). These studies also showed lymphoma cells on the surgical border. The patient was referred to pediatric oncology center for chemotherapy. Primary rectal lymphoma in childhood is extremely rare; therefore, the possibility of malignancy in rectal polyps should be considered in the pediatric patients.