We report a case of focal hematopoietic hyperplasia in the rib of a 24-year-old woman. This is only the fourth case to be reported in the English literature, all of which have involved the rib. Radiologically they all manifested as an expansive and radiolucent lesion and contained ill-defined areas of increased density or calcification. Histologically, all have been characterized by mixed areas of hypercellular marrow and fatty marrow. The lesion is considered a form of pseudotumor. Treatment in our case was by wide marginal excision of the rib.