Given the decline in growth momentum in the manufacturing sector in many OECD countries, the role of knowledge-based capital has emerged as a key driver for sustained growth. While empirical studies on estimating knowledge spillovers have usually been undertaken at the country level, the spillover effects can be more definitive only if the analysis is conducted at the industry-level. This paper therefore attempts to identify spillovers by disentangling technological innovations into intra- and inter-national knowledge innovations at industry level in driving per capita output growth. Our main findings are first, that there is evidence for a robust positive relationship between R&D, human capital and output growth across these countries at industry-level. Second, the potential of international spillover gains is greater in countries with higher human capital and in industries whose pattern of production is more R&D oriented, import intensive, and dependent on vertical FDI. Finally, significant heterogeneity is found between high and low-tech industries with high-tech group displaying greater knowledge spillovers, suggesting that low-tech industries need to be more innovative in order to absorb the technological advancements of domestic and international rivals.