The article assesses the impact of final demand for domestic products on the innovative activity of Polish enterprises. The activity is analysed in terms of their involvement in research and development (R&D) processes, which are considered crucial for an economy to be able to create a stock of knowledge. The main purpose of the analysis is to identify products that contribute to the largest increases in enterprises’ R&D expenditures. To study the effect of final demand on enterprises’ R&D activity, the input-output analysis method has been adopted. The presented analysis is part of author’s research on the intersectoral diffusion of knowledge in the Polish economy.