Background and Objective: The major complication of gentamicin antibiotic is nephrotoxicity which limited its clinical use. The current study was conducted to evaluate the possible protective effect of Beta vulgaris L. subsp. cicla var. flavescens (Swiss chard) against gentamicin-induced nephrotoxicity and hepatotoxicity in rats. Methodology: Twenty four rats were divided into 4 groups, group 1served as control. Group 2 to group 4 were intraperitoneally (i.p.) injected with gentamicin at a dose of 80 mg kg–1 body weight daily for 15 days. Swiss chard extract was orally administrated 1 week before and along with gentamicin treatment to groups 3 and 4 at doses of 300 and 600 mg kg–1 body weight daily, respectively. Results: The results revealed that, gentamicin significantly altered serum levels of kidney and liver markers as well as tumor necrosis factor alpha (TNF-α). These results were associated with significant changes in urinary urea, creatinine, micro-total protein (Micro TP) and vascular epithelial growth factor (VEGF) levels. A significant decrease in renal and hepatic reduced glutathione (GSH) levels, glutathione peroxidase (GSH-Px), catalase (CAT) and superoxide dismutase (SOD) enzymatic activities with a significant decrease in the expression levels of SOD1 and GSH-Px genes were also observed. In contrary, a significant increase in malondialdehyde (MDA), protein carbonyl levels and caspase-3 gene expression levels were also detected in gentamicin treated rats. Pretreatment with Swiss chard, dose dependently, ameliorated such altered changes. In harmony with this line, Swiss chard greatly decreased the severity of renal tubular and hepatic necrosis induced by gentamicin. Conclusion: Swiss chard leaf extract can attenuate gentamicin-induced nephrotoxicity and hepatotoxicity possibly by its antioxidant, anti-inflammatory and anti-apoptotic properties.