This study was designed to examine the effects of selenium nanoparticles (SeNPs) coated with gallic acid (GA) on testis in azoospermic rats. Thirty-six adult Wistar rats were assigned to six groups: control (1 ml intraperitoneal (i.p.) phosphate-buffered saline (PBS) for 7 consecutive days), SHAM (single i.p. injection of 1 ml of 8 % dimethyl sulfoxide (DMSO)), BUS (single i.p. injection of busulfan (BUS) 30 mg/kg body weight), GA (single i.p. injection of BUS 30 mg/kg on day 1, 100 mg/kg body weight GA from days 2–7), SeNPs (single i.p. injection of BUS 30 mg/kg on day 1, 0.5 mg/kg body weight SeNPs from days 2–7), and SeNPs-GA (single i.p. injection of BUS 30 mg/kg on day 1, 0.5 mg/kg body weight SeNPs-GA from days 2–7). Subsequently, serum levels of testosterone and insulin-like growth factor-1 (IGF-1), antioxidant markers, sperm parameters, and histological parameters were evaluated. The results showed that BUS injection induced azoospermia in rats by causing oxidative stress and testicular tissue damage. In contrast, co-administration of SeNPs and GA showed significant improvements in testosterone and IGF-1 levels, antioxidant status, testicular tissue characteristics, and sperm parameters. Overall, the findings suggest that GA-coated SeNPs offer therapeutic potential in BUS-induced azoospermic models.