Senility and obesity are closely related to problems in various organic systems, including the male reproductive apparatus. Thus, senility and obesity are two factors that favor the triggering of changes in innumerable parameters in the male reproductive system, ranging from morphological, to endocrine and physiological changes. Considering such damages, this study evaluated the testicular changes, at the stereological and pathological level. 36 FVB mice were used, and these were distributed in 3 groups: YG (young), SE (senile) and SHD (senile + high-fat diet). After 60 days, the animals were euthanized and their testes were collected for histological analysis. Afterwards, they were photographed under an Olympus BX41 optical microscope coupled to the Olympus Q Color 3 digital camera. The stereological and histopathological analyses were performed with IMAGE PRO PLUS 6.0 software, while the statistical analysis was run with the PRISM 5 STATISTIC software. Through the stereological evaluation, the tubular epithelial proportion was found to be reduced in SE compared to YG, which is corroborated by the significant increase in histopathological characteristics: degeneration, diffuse atrophy and tubular vacuolization. On the other hand, the SHD group showed an increase of this character in relation to SE, also accompanied by a significant increase of histopathological characters: degeneration and tubular vacuolization, germ cell depletion, and accumulation of atypical residual bodies. The intertubular portion percentage presented significant increase for SE and SHP, compared to YG, which was corroborated by the formation of interstitial edema and the presence of inflammatory infiltrates. The tubular lumen volume showed significant reduction in the SE group, compared to YG, and an increase in the SHP. Therefore, it can be observed that the high-fat diet accompanied by the senility factor favors, significantly, the testicular tissue damage, which hightlights inflammatory processes as well as tubular degeneration, and, consequently, the male fertility reduction.