The structure of interstitial cells of Leydig in the scrotal and abdominal testes of adult West African dwarf goats was studied utilising light and electron microscopy. The Leydig cells in both testes were scattered singly, in cords or clusters in the intertubular connective tissue in close proximity to vascular elements. The intertubular connective tissue in the abdominal testes was however much wider because of the hypoplasia of the seminiferous tubules. While the cells of the scrotal testes exhibited non-granular, pale staining cytoplasm, those of the abdominal testes were darkly staining and the majority contained coarse intracytoplasmic osmiophilic granules Interspersed amongst these cells were adipose cells occasionally distributed overall. With the electron microscope, it was found that agranular endoplasmic reticulum, Golgi apparatus and mitochondria were more prominently developed in the scrotal testes. In marked contrast, there were numerous lipid droplets in the cytoplasm of the Leydig cells in the abdominal testes. Furthermore, the cytoplasm of several of these cells showed evidence of degeneration. It is concluded that, contrary to observations in the experimentally induced condition, abdominal retention of testes in natural unilateral cryptorchidism induces alterations in the light microscopical and ultrastructural features of the Leydig cells of West African dwarf goats, changes which possibly can be ascribed to the chronic decline in testicular blood flow and the elevated temperature of the abdominal environment.