In the present work, the effect of exposure to cigarette smoke on male fertility in rats, as characterized by changes in the relative weight of sex organs, epididymal sperm count, activity of marker enzymes and DNA damage was evaluated. Exposure of rats to cigarette smoke caused a gradual decrease in total body weight gain and relative weight of the epididymis and seminal vesicles by 30 and 40% respectively. Epididymal sperm count was reduced significantly by 25% (P ≤ 0.05) after 2 weeks and by 41% (P ≤ 0.001) after 4 weeks of exposure. Exposure to cigarette smoke had reduced the activity of sorbitol dehydogenase by 18% (P≤0.05) and increased the activity of lactate dehydrogenase by 28% (P ≤ 0.05). The changes in both key enzymes were significant, which reflected the inhibitory effect of cigarette smoke on spermatogenesis and sperm maturation. The toxic effect of exposure could be explained partially due to induction of DNA damage and oxidative stress as shown by the significant increase in serum 8-hydroxy-2`-deoxyguanosine from 22.83 to 37.33 ng ml-1 blood.