["Business Ethics, the Environment &Responsibility, EarlyView. ", "\nABSTRACT\nNonprofit organizations (NPOs) promote themes closely relating to corporate social responsibility (CSR). However, only a few companies implement CSR. Hence, the internal and external factors that influence companies to implement CSR are worth exploring. Using a sample of 951 mid‐ and large‐sized Czech companies, we examine the internal and external factors that drive CSR implementation. By applying a partial least‐squares structural equation model, we test the role of perceived awareness about CSR, knowledge and skills, and willingness to implement CSR and the interactions between companies and NPOs. Results indicate that willingness, awareness, and skills increase the intensity of CSR implementation, while skills and knowledge are the most influential factors. The relationships between companies and NPOs underline the independence of companies and the limited impact of NPOs on Czech companies' CSR decisions.\n"]