Rectal polyps are relatively common in children and most often present as painless rectal bleeding after defecation. By contrast, rectal prolapse caused by an underlying rectal polyp is uncommon, especially in pediatric patients. Because intermittent prolapse may have resolved by the time of clinical examination, the diagnosis can be difficult to establish. A previously healthy 1-year-old boy was referred to the pediatric surgery outpatient clinic because of a 6-month history of intermittent protrusion of a mass through the anus after defecation. The episodes initially occurred approximately three times per day but gradually increased to six times per day. Physical examination showed no definite perianal abnormality; however, a photograph provided by the patient’s mother showed a protruding anorectal mass, raising suspicion for rectal prolapse associated with a polyp. Colonoscopy revealed a large pedunculated rectal polyp, measuring approximately 47×34×25 mm, with a short stalk located approximately 15 cm proximal to the anal verge. The patient underwent transanal excision under general anesthesia. Histopathological examination confirmed a Peutz-Jeghers-type hamartomatous polyp. The postoperative course was uneventful, and no recurrence was observed during 3 years of follow-up. Rectal polyps should be considered in the differential diagnosis of recurrent rectal prolapse in infants and young children. Caregiver-provided photographs can help establish the diagnosis when the lesion is not visible during examination. In selected pediatric patients with large rectal hamartomatous polyps presenting with recurrent prolapse, transanal excision may provide safe and effective treatment.