This paper proposes that both the resource‐based view and institutional theory predict a positive relationship between the number of patented environmental innovations and non‐environmental innovations held by a firm, because they both are subject to the influence of similar factors. However, while the resource‐based view predicts that technological differences between the patented environmental innovations owned by a firm and those in the industry as a whole will positively affect the firm's environmental innovations, the institutional perspective predicts a negative relationship. Our results derive from a sample of 5537 environmental patents from 59 large companies in the electrical components and equipment industry worldwide, and show a positive relationship between patented environmental and non‐environmental innovations in a firm, but a negative influence on the number of the firm's patented environmental innovations resulting from differences between the firm's environmental technologies and those generally prevalent in the industry. Copyright © 2015 John Wiley & Sons, Ltd and ERP Environment