Introduction: This study aimed to show the potency of curcumin as an antiapoptotic agent that decreases the apoptotic index in the cochlea lateral wall in ototoxic rat models. Materials and Methods: A total of 24 Rattus norvegicus were divided into eight groups: Group 1 (control group), Group 2 (gentamicin (+)), Group 3 (gentamicin + curcumin 20 mg/day), Group 4 (gentamicin + curcumin 40 mg/day), Group 5 (gentamicin + curcumin 20 mg/day for 7 days), Group 6 (gentamicin + curcumin 40 mg/day for 7 days), Group 7 (curcumin 20 mg/day for 3 days + gentamicin), and Group 8 (curcumin 40 mg/day for 3 days + gentamicin). After the division, the rats were terminated in order to measure the apoptotic index using a terminal deoxynucleotidyl transferase (TdT) dUTP nick-end labeling (TUNEL) assay in the fibroblasts of the cochlea lateral walls. The data were analyzed using analysis of variance (ANOVA), and P < 0.05 was used as the cut-off for statistical significance. Results: Administration of gentamicin showed significant differences (P < 0.05) in the apoptotic index. Groups undergoing curcumin treatment at a higher dose (200 mg/kg bw) and the prevention groups showed significant differences compared with groups not treated with curcumin Conclusion: This study concluded that the apoptotic index can be decreased by curcumin and has a preventive benefit toward ototoxic rat models. The administration of curcumin depended on the dose and duration. © 2018, Mashhad University of Medical Sciences.