Cisplatin (CDDP) may induce nephrotoxicity through oxidative stress, DNA damage, and inflammation. This study was performed to evaluate the antioxidant and anti-inflammatory effects of allicin and ascorbic acid (AA) and investigate the nephroprotective efficacy of their combination against CDDP-induced intoxication. Rats were divided into seven groups: control, allicin (10 mg/kg for 14 days), AA (20 mg/kg for 14 days), CDDP (7 mg/kg as a single dose on the seventh experimental day), CDDP-allicin, CDDP-AA, and CDDP-allicin-AA (at the aforementioned doses). The administration of CDDP induced marked body weight loss and renal damage, manifested by significant increases (p < 0.05) in serum creatinine, urea, and uric acid levels and significant reductions in serum Na, Ca, and phosphorus concentrations, in addition to severe alterations in serum and renal tissue levels of tumor necrosis factor-α in comparison with control rats. Moreover, CDDP-intoxicated rats exhibited significantly (p < 0.05) higher lipid peroxidation, as well as lower levels of reduced glutathione and activities of glutathione peroxidase, superoxide dismutase, and catalase enzymes in the renal tissue, compared with control rats. The administration of allicin or AA significantly reduced (p < 0.05) the CDDP-induced changes in all the aforementioned parameters. Interestingly, allicin achieved comparable nephroprotection to AA in most assessed parameters; however, the restoration of normal serum and renal tissue concentrations of these parameters was more frequent in the CDDP-AA group. In conclusion, both allicin and AA showed significant nephroprotective effects against CDDP intoxication and their combination exhibited better protection than either agent alone. These results are probably mediated by their antioxidant and anti-inflammatory activities.