Purpose: The purpose of this study was to determine the effects of music therapy on postpartum stress and maternal attachment of puerperal women. Methods: The participants were puerperal women who agreed to participate in this study and through a convenience sampling, 84 puerperal women were recruited (40 in the experimental group, 44 in the control group). After measuring postpartum stress and maternal attachment, music therapy was provided to the experimental group over 60min, three times a week, and for 2 weeks. Then, postpartum stress and maternal attachment for the experimental and control group were measured again before discharge. The data were analyzed using the SPSS/WIN 14.0 program. Results: The first hypothesis that "the degree of postpartum stress for the experimental group who participated in music therapy would be lower than that of the control group" was accepted. The second hypothesis that "the degree of maternal attachment the experimental group who participated in music therapy would be higher than that of the control group" was accepted. Conclusion: These findings indicate that music therapy has positive influences on decreasing postpartum stress and increasing maternal attachment of puerperal women.