Cisplatin is an antineoplastic agent, used in the treatment of different types of malignant neoplasms. Side effects such as ototoxicity, nephrotoxicity, and bone marrow toxicity are the main limitations of its clinical use. The aim of the present study was to evaluate the possible effects of hyperbaric oxygen (HBO) therapy as a protective agent in cisplatin-induced ototoxicity in rats. A total of 30 adult Wistar rats (60 ears) were divided into five equal groups. Group 1 is a control group; group 2 is HBO therapy group; group 3 received 15 mg/kg cisplatin intraperitoneally; group 4 received 15 mg/kg cisplatin intraperitoneally and HBO treatment on the same day; group 5 received 15 mg/kg cisplatin intraperitoneally and HBO treatment 72 hours later. The effect of ototoxicity was measured with distortion product otoacoustic emission testing performed on the days 1, 3, and 7. Groups 4 and 5 that received HBO treatment after cisplatin had better signal-to-noise ratio (SNR) values compared with group 3 that received only cisplatin (P<0.05). Compared with group 5, group 4 (same day HBO treatment) had better SNR values (P<0.05). HBO was found effective for prevention of cisplatin-induced ototoxicity in rats. Our study differs from other studies regarding using a promising treatment, which does not expose subjects to extra stress. Cobanoglu, Vuralkan, Arslan, Mirasoglu, Toklu (2019). Is Hyperbaric Oxygen Therapy Effective in Cisplatin-Induced Ototoxicity in Rats? Clinical and experimental otorhinolaryngology, 2019 Feb;12(1):66-71. https://www.ncbi.nlm.nih.gov/pubmed/30189717