Abstract
This paper investigates the relationship between public service motivation (PSM) and employee performance by adopting a notion of performance which incorporates extra-role behaviours, such as the propensity to engage in unpaid overtime, organizational citizenship behaviours, absenteeism and organizational deviance. It does so in an underexplored part of the public sector, namely prisons. As well as providing new explanatory mechanisms for understanding the outcomes of PSM behaviour and exposing the dark side of PSM, this paper contributes to debates about the significance of PSM and the consequences of its absence.