Non-
ossifying fibromas are common benign lesions of tubular long bones. There is recognized association of these bony lesions with neuro
fibromatosis type 1 although the presence of
non-
ossifying fibromas in familial members with the condition has not previously been reported. We report two siblings with neuro
fibromatosis and radiological evidence of multiple lower limb
non-
ossifying fibromas. Both patients presented with pain in the knees and a pathological fracture was observed in one case. Patients with multiple
non-
ossifying fibromas should be examined carefully for other evidence of neuro
fibromatosis.