Listening to relaxing music was found to reduce state anxiety and state anger among various populations. Nonetheless, the impact of relaxing music in prisons has not yet been studied. The current study examines the impact of relaxing music on levels of state anxiety and state anger among a random sample of 48 criminal prisoners. Main findings are as follows: (a) level of state anxiety decreased among the treatment group compared with the comparison group and (b) level of state anger decreased among the treatment group compared with the comparison group. Findings are discussed in light of other studies that have shown positive effects of exposure to relaxing music on levels of anxiety and anger among other populations. The final part of the study provides practical recommendations for prison administrators regarding implementation of programs of relaxing music in various prison facilities.