Calorie restriction (CR) has been reported to have pro-longevity effects in a myriad of species. However, a deleterious effect of CR on reproduction is also observed, though seemingly negligible if CR is very mild. Full or partial suppression of reproduction by CR is worthy of concern when envisioning the use of this methodology to prolong lifespan in humans. Our aim was to investigate the effects of mild CR on several reproductive parameters, such as the onset of puberty, fertility, reproductive organ biometry, testis morphometry and testosterone and cholesterol plasma levels. Therefore, male Wistar rats were subjected to 30%CR from age 24 days until the ages of 50 and 150 days. Age-matched animals received food ad libitum (AL) and served as controls. The day of onset of balano-preputial separation, indicative of puberty, showed no difference between diet groups. In relation to the fertility parameters evaluated, considering mainly the number of pups per female, there was a trend for better performance in CR rats. Body weight, as well as the absolute and relative weights of the epididymal fat pad, was reduced by CR at both ages investigated, whereas testosterone and cholesterol plasma levels were not changed. The weight of ventral prostate, also the tubular diameter and luminal size were smaller in CR rats at age 50 days, but seemed to recover later since no differences were observed at age 150 days. In conclusion, our results suggested that 30%CR does not compromise reproduction in male Wistar rats.