In this study, we observed that obesity induced an increase in oxidative stress in the testicular tissue, which simultaneously increased the mRNA and protein levels of NF-κB, TNF-α, and IL-1; decreased the mRNA and protein levels of the anti-inflammatory cytokine IL-10; and decreased the mRNA and protein levels of key testosterone synthases SF-1, StAR, and P450. Here, STAR is linked to obesity due to melanocortin 4 receptor deficiency.