Introduction: Disorders of consciousness are the most common complications after head injury. Patients with traumatic coma, due to their nature, are more likely to show impaired physiological indices. This study aimed to investigate the effect of listening to nature sounds on the level of consciousness and physiological indices in patients with traumatic coma. Methods: 60 patients with traumatic coma admitted to the Intensive Care Units (ICUs) of Shohaday-e-Haft-e-Tir Hospital in the city of Tehran, Iran, and Imam Hossein Hospital in the city of Shahroud, Iran, were randomly selected in 2017 to participate in this randomized clinical trial. They were randomly assigned to two groups of control and intervention through randomized block method. The patients in the intervention group listened to nature sounds twice a day (each time for 30 minutes) for two weeks. The level of consciousness of the patients was measured and evaluated using Glasgow Coma scale before and one and two weeks after the intervention. Also, the physiological indices of the patients were examined and recorded immediately, 30 minutes and 2 hours after the intervention on the first day of the intervention. The data were analyzed using SPSS 21 and through independent t-test, repeated measures analysis of variance, Fisher and Chisquared tests. Results: The number of the patients reaching complete consciousness in the intervention group was more than that in the control group (p=0. 001). In the intervention group, immediately after the intervention, the mean pulse, systolic blood pressure and mean arterial pressure were lower than other times. Conclusion: According to these results, listening to nature sounds increased the level of consciousness of the patients, decreased the duration of coma and caused an immediate and short-term decrease in physiological indices.