This study was aimed at determining the effects of corn and wheat gluten, used as dietary protein sources, on live weight gain, sperm quality and the histology of the testes and accessory glands in male rats. For this purpose, 20-day-old 24 male Wistar albino rats were randomly assigned to three groups. Group 1 (Control), Group 2 and Group 3 were fed on a basal ration supplemented with high levels of soybean meal, corn gluten and wheat gluten, respectively, as a protein source. At the end of the study, when compared to Group 1, live weight values were determined to have increased in Group 3 and to have decreased in Group 2 (p < .05). Furthermore, sperm density, sperm motility, the dead/ live sperm ratio and testes weight were determined to have significantly decreased in Group 2, in comparison to Groups 1 and 3 (p < .05). The percentages of abnormal spermatozoon, and head, acrosome, mid-piece and tail abnormalities were high in Group 2 (p < .05). Histological examination demonstrated that, in Group 2, the diameter of the Tubulus Seminiferous Contortus (TSC) and the size of the Tubular Epithelial Cells (TE) were small, and the tubular and anatomical structure of the testes were shrunken and altered. Group 2 also presented with connective tissue increase and alveolar lumen enlargement in the prostate gland, and with connective tissue thickening, muscle tissue increase and secretory capacity decrease in the seminal vesicle (p < .05). Moreover, in Group 2, the Gl. Bulbourethral (Cowper's gland) presented with a decreased size and dilatations in the mucous structures. In a result, based on the findings obtained in this study, it is suggested that high levels of dietary corn gluten adversely affect live weight, sperm quality, and the testes and accessory glands.