The objective of this paper is to develop the model that can be used to explain the amount of research and development (R&D) expenditures of large and mature companies. The re-search methodology is based on real options approach. We model companies’ R&D expen-ditures as payments for the real option, which is the right of a company to invest in real assets in the future, and therefore to ensure business development. The main result is a valuation model, which includes several relevant factors. While existing research papers apply real options approach mostly to the R&D projects of particular companies or within particular industries and situations, the current paper applies the corresponding methodol-ogy in general and aggregated setting. We hope that it will contribute to understanding of R&D intensity in large innovative companies.