The purpose of this paper is to explore the roles of frontline employees (FLEs) in service innovation processes and how they contribute to these roles. In the literature, FLEs are argued to play an important role in service innovation; however, neither the potential types of roles nor what taking on these potential roles means to FLEs, have previously been studied. This study investigates FLEs' actions in different types of service innovation processes. Based on analyses of eight different service business units, FLEs are identified as having either of two sets of roles: (1) leading roles as idea creators, developers and implementers, or (2) supporting roles as problem reporters, advisors and executors. The analysis provides managers with guidelines which can help them to better utilize FLEs as contributors to service innovation, either as leading or supporting actors. These imply different management challenges, which are discussed. Advice on how to tackle these challenges is given on the basis of the findings.