This study investigates the relationship between labour market externalities and regional growth based on real labour flows. In particular, we test for the importance of labour mobility across so-called skill-related industries. We make use of a sophisticated indicator that measures the degree of skill-relatedness between all industries, and we employ actual labour flows between 435 4-digit industries within 72 Swedish functional labour market regions to estimate how labour market externalities are related to regional growth in the period 1998-2002. Both our fixed effect models and GMM-estimates demonstrate that a strong intensity of intra-regional labour flows between skill-related industries impacts positively on regional productivity growth, but less so on regional employment growth. Labour mobility between unrelated industries tends to dampen regional unemployment growth while a high degree of intra-industry labour flows is only found to be associated with rising regional unemployment.