We describe a female infant who presented with severe intracranial bleeding and was found to have a hereditary deficiency of vitamin K-dependent coagulation factors. She also had mild stippling of the left femoral epiphysis and shortness of the distal phalanges of the fingers. We studied the possible relationship between these abnormalities and a peroxisomal defect and followed their responses to treatment with vitamin K. The level of vitamin K-dependent clotting factors returned to near-normal following treatment with pharmacological doses of vitamin K, but there was no effect on the skeletal abnormalities.