This study aims to examine and analyze the effect of Work-Life Balance in Islamic Perspective (WLBIP) and Organizational Citizenship Behavior in Islamic Perspective (OCBIP) on service performance. In addition, this study also tests and analyzes the effect of OCBIP's role in mediating the WLBIP effect on service performance. Respondents of this study are managers and staff who work at Baitul Maal Wa Tamwil or Sharia Financing and Savings and Loan Cooperatives (KSPPS) in Yogyakarta Special Region, which is spread across the city and districts with a total of 158 respondents. The sampling technique is conducted by purposive sampling. Meanwhile, the statistical technique uses AMOS 21. The results show that (1) WLBIP has an effect on OCBIP, (2) WLBIP has no effect on service performance, (3) OCBIP has an effect on service performance, and (4) OCBIP is able to mediate the effect of WLBIP on service performance.