The impact of product owner, Scrum master and developer mental models on Scrum teams has been investigated in this research. Twelve semi-structured interviews with practitioners from three Scrum teams in New Zealand government indicated that the product owner mental model is crucial for positive Scrum outcomes. A complementary mental model between the product owner and the development team appears to drive the highest client and team satisfaction. Across all participants, Customer- and Team-oriented mental models coincided with the highest levels of client and team satisfaction. This preliminary evidence shows that mental models can contribute to positive Scrum outcomes. It sheds new light on how Scrum can be effectively managed in the public sector by considering individual mental models and team mental models. The mental model perspective offers organisations a different way to evaluate the operation of Scrum teams.