A Nigerian patient is described with megaloblastic anemia due to vitamin B12 deficiency. The deficiency resulted from malabsorption of the vitamin, but no other abnormal functioning of the gastrointestinal tract could be demonstrated. The patient did not have addisonian pernicious anemia. He had remarkable hyperpigmentation of the skin, especially of the palms of the hands. What is known of possible connections between megaloblastic anemias and melanin metabolism cannot explain this hyperpigmentation.