This study evaluated the effects of diet containing taro flour on hormone levels and the seminiferous tubules morphology of rats. After weaning, the male rats were divided into two groups (n=12 each): control group (CG) treated with control diet and taro group (TG), fed with 25% taro flour for 90 days. Food, caloric intake, mass and body length were evaluated at experiment end. Testis followed the standard histological processing. Immunostaining was performed using an anti-vimentin antibody to identify Sertoli cells. In histomorphometry, total diameter, total area, epithelial height, luminal height and luminal area were analyzed. The testosterone levels were performed using the radioimmunoassay method. Group TG presented (P<0.05): increase in mass, body length, testicular weight, histomorphometric parameters and hormonal levels. Food intake, calorie and Sertoli cells not presented statistical differences. The taro promoted increase in the testicles parameters and hormones.