Purpose: This study aimed to examine the effects of cognitive behavior therapy for insomnia (CBT-I) based on the mobile social networking service(SNS) on dysfunctional beliefs and attitudes about sleep, sleep quality, daytime sleepiness, depression, and quality of life among rotatingshiftnurses in a hospital in Korea. Methods: A nonequivalent control group pre-post test design was used. The participants included 55 nurseswith rotating three-shift work (25 in the experimental group and 30 in the control group). For the experimental group, CBT-I using mobile SNSwas provided once a week for 60 minutes over six weeks. Data were analyzed using descriptive statistics, c2-test, independent samples t-test,and Mann-whitney U test with the SPSS 21.0 program. Results: In the homogeneity test of the general characteristics and study variables, therewere no significant differences between the two groups. Nurses in the experimental group had significantly lower scores on dysfunctional beliefsand attitudes regarding sleep and sleepiness than nurses in the control group. Nurses in the experimental group had significantly higher scoreson sleep quality and quality of life than nurses in the control group. Conclusion: These findings indicate that using the mobile SNS-based CBT-I isfeasible and has significant and positive treatment-related effects on rotating-shift nurses’ irrational thoughts and beliefs in association withsleep, sleep quality, daytime sleepiness, and quality of life. These contribute to expanding our knowledge of rotating-shift nurses’ sleep issues andtheir preferences for intervention.