Adult male albino rats were treated with 0.5 mg and 0.75 mg morphine/100 g body weight intraperitoneally for 30 days. All the animals were autopsied on $31^{st}$ day. Epididymis and vas deferens were dissected out, weighed and processed for histological and biochemical studies. Morphine has caused a reduction in the weight of epididymis and vas deferens in both the doses of drug treated groups. The total cholesterol content is increased while protein, DNA and RNA contents and epididymal sperm counts are decreased. The acid phosphatase content is decreased 10.12 $pm$ 0.11 in caput, 9.26 $pm$ 0.30 in cauda of epididymis and in vas deferens 8.14 $pm$ 0.15 in 0.5 mg treated groups and in 0.75 mg treated rats shows 9.52 $pm$ 0.27 in caput, 9.14 $pm$ 0.18 in cauda of epididymis and in vas deferens 7.84 $pm$ 0.11is decreased, whereas alkaline phosphatase is increased. The surface epithelial cell height of these ducts is reduced and secretory activity is inhibited with the disruption of epithelial cell projections. The gravimetric and histometric changes of epididymis and vas deferens may be due to non-availability of androgens in morphine treated rats.