A shortcoming of traditional endogenous growth approaches is their assumption that the stock of knowledge is generally accessible across space. The purpose of this paper is to analyse the contribution of R&D to economic growth in Swedish municipalities, taking account of the variation in R&D accessibility among different municipalities. We argue that the interaction possibilities at different spatial scales can be properly represented by an accessibility approach which discounts interaction potentials using travel time distances. Hence, the total accessibility of a municipality is divided into (i) intra-municipal, (ii) intra-regional and (iii) extra-regional accessibility to R&D. The main result of the analysis is that knowledge accessibility in a given period has a statistically significant effect on the growth in value-added per employee in subsequent periods. Furthermore, the knowledge resources in a given municipality tend to have a positive effect on the growth of another municipality, conditional on the municipalities belonging to the same functional region. The paper also demonstrates that knowledge accessibilities do not affect growth homogenously across municipalities. By dividing the full sample into three categories, the paper shows that knowledge investments have the largest effects on regional growth in municipalities belonging to a large functional region, but not necessarily in the largest municipality in the region.