Abstract: Adult males of the quail Coturnix coturnix were exposed to lead acetate trihydrate in drinking water (0.1, 0.25, 0.5 and 1% for 1 to 6 months) to investigate testicular histological alterations induced by lead intoxication. Chronic exposure to subtoxic concentrations of lead caused vascular, interstitial and tubular histological alterations that included interstitial arterial congestion, endothelial cell hyperplasia, interstitial fibrocyte hyperplasia, Leydig cell degeneration, intertubular edema, thickening of the seminiferous tubular basement membrane, spermatocyte degeneration, pyknosis and desquamation. Tubular atrophy and arrest of spermatogenesis were also observed. Taken together, the histological findings of this study indicate that chronic exposure to lead produces significant histological alterations in the testes, which may eventually lead to complete arrest of spermatogenesis.