Abstract This paper examines the co-evolution of public governance and innovation, and proposes an adaptation of Hartley's model to take into consideration such co-evolution. This model is then applied to a longitudinal case study of the digitalization of Roskilde University Library. The theoretical and empirical analysis yields four main results. First, it is shown that the transition from a New Public Management approach towards a Networked Governance mode implies a greater distribution of knowledge and innovation across different organisational levels within public administrations. Interactions between such organisational levels crucially affect the development of new public services. Second, a more articulated view of users in public sector innovation is developed. It is argued that: (i) users play distinct roles at different stages in innovation processes, with relatively greater involvement in minor incremental changes; (ii) user-driven innovations have significantly increased with the diffusion of ICTs and Web based public services; and (iii) complex innovations are facilitated by face-to-face meetings between public servants and users. Third, it is suggested that changes in governance modes affect the balance between the different actors involved, thus influencing the nature and intensity of innovation. Fourth and finally, it is argued that the transition towards a networked governance approach requires information policies which persist over time, and are designed to increase collaboration between different (public and private) actors.