Juvenile polyposis coli associated with neurofibromatosis in a 24-year-old white man is reported. Juvenile polyposis coli is now recognized as a distinct clinical entity. Differentiating it from the other hereditable gastrointestinal polyposis syndromes is important because of the lack of reported malignancies. Radical surgery is unnecessary unless warranted by the clinical features of bleeding or diarrhea. The known gastrointestinal and extra gastrointestinal associations with juvenile polyposis coli are reviewed along with the gastrointestinal manifestations of neurofibromatosis. This is the first reported association of neurofibromatosis with this unusual syndrome.