An enzyme-linked immunosorbent assay on the basis antialcohol dehydrogenase III (ADH III) monospecific antiserum has been devised. The immunoreactive protein content determined in two samples of human testis autopsy material was 1,288 and 1,047 mg/g of wet weight. ADH III has been revealed in all types of human testicular cells with the maximal content in spermatocytes and spermatogonia.