The purpose of this randomized controlled trial was to examine the effects of background music on quality of sleep in elementary school children. Convenience sampling was used to recruit a total of 86 fifth graders (43 boys and 43 girls) from an elementary school in a city in Taiwan. Subjects were randomly assigned to the experimental groups (n = 45) and the control group (n = 41). Subjects in the experimental group were given a 45-minute CD of music at naptime everyday and bedtime each night for 3 consecutive weeks. Sleep quality was measured using the Pittsburgh Sleep Quality Index (PSQI) at pretest and 3 weekly posttests. Repeated measures MANOVA was used to examine group differences across time. Results showed that subjects who received background music at naptime everyday and bedtime each night for 3 consecutive weeks had significant improvement in global sleep quality over time. Improvements were also observed in all 6 components of the PSQI although significant improvements were only observed in sleep duration and sleep efficiency. Some shortcomings of this study include the use of convenience sample, possibility of a Hawthorne effect, lack of objective measurements, and the use of non subject's preferred music.