Albino rats were given a sweetened caffeine beverage as their sole source of fluid throughout their reproductive period. The average daily consumption of caffeine by each animal amounted to 40–50 mg per kilo body weight. The reproductive capacity as judged by the number of litters and number of offspring was not impaired by the daily ingestion of caffeine. There were no pathological changes in the testicles of the test animals except for the natural histological degenerative changes which were observed in about equal frequency in the control animals. The rate of growth of the animals on the caffeine beverage was the same as that of the controls.