Cancer-related cognitive impairment (CRCI) is prevalent among cancer patients. A critical disparity in the CRCI field is that most pre-clinical studies have been conducted on young cancer-free male rodents, although CRCI predominantly affects breast cancer and ovarian cancer women survivors. Since oxidative stress is widely implicated in the development of CRCI, we developed an ovarian cancer xenograft rat model of CRCI in Cr:NIH-RNU female rats to examine whether administration of the antioxidant N-acetylcysteine (NAC) prevents cisplatin-induced CRCI without altering its anti-cancer efficacy. In vitro, delayed treatment with NAC (10 h) following cisplatin treatment in the human ovarian cancer cell line SKOV3.ip1 did not decrease cisplatin's anti-cancer efficacy while mitigating hippocampal dendritic branching damage and neuronal apoptosis. Rats received subcutaneous and intraperitoneal implantation of SKOV3.ip1 cells. Rats received one cisplatin (5 mg/kg) injection every two weeks for a total of four cycles, with or without NAC (250 mg/kg/day), given for five consecutive days during cisplatin treatment. NAC was administered 10 h after cisplatin, based on our in vitro data. Cognitive testing was performed six to seven weeks after treatment cessation. In vivo, cognitive impairments were observed in tumor-bearing rats in the vehicle and cisplatin-treatment groups, while delayed NAC prevented cognitive impairments. Delayed NAC administration did not affect cisplatin-induced tumor volume reduction. Our study supports using NAC to mitigate cisplatin-induced CRCI through the novel development of an ovarian cancer rodent model. This study highlights the importance of developing clinically relevant tumor-bearing models to elucidate the underlying mechanisms associated with CRCI, which will aid in identifying potential therapeutic agents for preventing CRCI.