The fine structure of cells capable of phagocytosing spermatozoa in the testes and epididymes of monkeys and men was studied by means of transmission and scanning electron microscopy. Both resident cells, such as Sertoli cells and epithelia of the rete testis, and free cells, such as macrophages (spermatophages) were found to phagocytose spermatozoa or fragments of spermatozoa in the seminiferous tubules and excurrent ducts. The spermatophages develop from precursor cells which invade the seminiferous tubules. After phagocytosis of spermatozoa they increase in size and sometimes possess more than one nucleus. Large spherically shaped spermatophages are found in the epididymis. In the rete spaces of Macaca fascicularis spermatophages are able to penetrate the rete epithelia and reside in the subepithelial connective tissue layers. Spermatophagy is frequently seen in the gonads of older men and in certain cases of oligozoospermia. In Macaca an increased number of spermatophages occurs at the end of the spermatogenetic season.