Introduction: One of the sources of stress is business tension. Although any sort of employment may involve stress yet health-related jobs appear to be more stressful. Nurses confront critical situations and professional problems. Hence, this study, aimed to determinate the effect of music on critical unit nurses stress.

Methods: The research was a clinical trial. Thereby, 127 nurses, who were working in critical units, were randomly selected and allocated either to the intervention or the control group. Data was collected before applying the intervention for each of the two groups by means of the Garry Taft and Anderson questionnaire. The intervention group was exposed to their preferred music for 12 weeks, three times each week, 20 minutes each time. After the end of the 12-week course, the mentioned questionnaire was answered by this group and simultaneously by the control group. To analyze the data, the SPSS software, version 12, was used.

Results: The distribution of demographics properties of the two groups was similar. There was a statistical difference in the stress level of the intervention group, before and after the intervention. Also, there was a meaningful statistical difference between the two groups, after the intervention.

Conclusions: According to the achieved results of this study, music has a positive effect on decreasing nurses stress level. The application of music in critical hospital units should be discussed and deliberated.