The effect of administration of potassium dichromate to male mice at a dose of 400 ppm in drinking water for 8 weeks
on the reproductive system was studied. Epididymal sperm count, motility, morphology and viability were investigated. The antioxidant status of testes was also studied. Serum testosterone level was measured and histopathological alterations in brain and testis were recorded. It has been demonstrated that chromium administration reduced sperm count and progressive motility while increased the number of immotile sperm. The percentages of normal sperm morphology and viability were reduced. Testicular malondialdehyde (MDA) level increased while reduced glutathione (GSH) concentration was reduced. The activities of testicular superoxide dismutase (SOD), glutathione reductase (GR) and catalase (CAT) were inhibited. Serum testosterone level decreased as a consequence of chromium intoxication. Histopathological findings revealed chromatolysis and sever loss of Purkinje cells in cerebellum. The cerebrum showed congested blood vessels with perivascular cuffing, increased number of glia cells, neuronophagia and diffuse vacuolation. The testis showed sever necrosis and loss of spermatocytes with wavy basement membrane of seminiferous tubules, sever congested blood vessels with mononuclear cells infiltration in the interstitial tissue, presence of some desquamated cells in the lumen of seminiferous tubule and vacuolation of the remaining spermatocytes. The toxic effects of chromium on the sperm parameters, testis and brain were ameliorated by daily co-administration of L-carnitine orally at a dose of 200 mg/kg body weight. This protective effect of L-carnitine may be attributed to its antioxidant activity as indicated by improvement of GSH level and activities of testicular SOD, GR, and CAT together with reduced MDA concentration.