The relationship between sales revenues per full time employee, research and development (R&D) expenditure and employment in Poland's most advanced enterprises was examined for 2007 using econometric modelling. The level of innovation intensity varied from 1% to 10%. The research demonstrated that knowledge resources and sales revenues are positively correlated and that the former is having an ever greater impact on the latter. Ceteris paribus, a positive correlation between R&D expenditure on the one hand and sales revenues on the other was observed even in enterprises with an innovation intensity of 1%. In enterprises with an innovation intensity of 1 – 10%, R&D expenditure contributed to a more efficient allocation and utilisation of labour resources. This was a significant factor in developing enterprises and enhancing their competitiveness.