We reviewed five cases of Uterine leiomyomas, each with a conspicuously, yellow cut surface, among 198 consecutive cases of surgically removed uterine leiomyomas. Their gross findings were not significantly different from ordinary leiomyomas except for their pale to bright Yellowish cut surface. Microscopically, multiple small clusters of clear cells were widely scattered in otherwise hypercellular leiomyornas in 4 of the 5 cases. Of those, one case gave a positive reaction of Oil-Red O stain. Ultrastructurally, clear cells corresponded to the degenerating smooth muscle cells with intracytoplasmic lipid vacuoles. The rest of cells showed myofibers undergoing varying degrees of degeneration. Focal accumulation of foamy histiocytes was associated with carneous degeneration in one case. We conclude that the yellowish leiomyoma of the uterus seems, in part, to reflect accumulation of a lipid substance in degenerating hypercellular leiornyoma, or possibly collections of xanthoma cells in secondary degeneration.