An increasing amount of research in the migration literature shows a positive association between migrant diversity and firm productivity. However, the potential bias due to unobserved heterogeneity remains a challenge. In this paper we analyse the impact of cultural diversity on firm innovativeness, while using finite mixture modeling to control for observed and unobserved heterogeneity. Recent availability of microdata has enabled us to construct a linked employee-employer dataset through merging datasets on both workers and firms. We explore the possible ways of firm-level knowledge exchange among the employees with different cultural backgrounds and its impact on firms’ product and process innovations. We find that workforce diversity is beneficial for innovativeness in capital-intensive sectors. It also positively impacts large firms that operate in high-level services, manufacturing, mining and R&D sectors, that are predominantly located in the non-urban areas in the Netherlands. In labour and land intensive sectors, the impact of cultural diversity on innovativeness is inconclusive.