Meckel diverticulum was diagnosed preoperatively as the cause of recurrent rectal bleeding in a 2-year-old child by means of a sodium pertechnetate Tc 99m scan. Although false-negative scans have been reported to occur in approximately 50% of all cases of Meckel diverticulum, the procedure should be considered in any case of unexplained, painless rectal bleeding, especially in pediatric patients.