This paper investigates the impact of applying systems thinking approach to service operations design on the Triple Bottom Lines (TBL) of sustainability. A survey was conducted with 95 service organizations that have implemented the systems thinking approach into their service operations. Using the Structural Equation Modelling (SEM) technique, results confirmed that systems thinking implementation in service operations has significant impact on the environmental and social dimensions of sustainability (p<0.05), but has no significant effect on the economic dimension. This is the first study empirically investigating the impact of systems thinking approach on the TBL of sustainability in service departments.