This study was performed to determine the effects of dietary vitamin E and soybean oil (a rich source of polyunsaturated fatty acids) on the sperm concentration and motility in male Sprague-Dawley rats. Rats with body weights between 250 - 300 gms were randomly allotted into five treatment groups with three animals each. The trial lasted 63 weeks inclusive of a one week acclimatization period. Rats were fed either CTRL (Base Diet + 5 % Soybean Oil + 3000 IU Vitamin E), BD Only (Base Diet Only), BDVitE (Base Diet + 3000 IU Vitamin E Only), BDSBO (Base Diet + Soybean Oil Only) or COMM (Imported Commercial Rat Pellets). At the end of the trial, the rats were euthanized and sperm concentration and motility were evaluated for both left and right testicles. It was found that although sperm motility had no significant difference across treatment groups, animals supplemented with adequate vitamin E and soybean oils had significantly higher concentration of sperms. It was also shown that vitamin E supplementation alone is more important than dietary fat supplementation in influencing sperm concentration in rats.