Abstract. This paper analyzes the main determinants influencing environmental innovators (i.e. firms developing or adopting environmental innovations) in Spain with respect to non-environmental innovators. Similarly to other contributions in the literature, our results show that Spanish environmental innovators respond to regulatory stimulus in the form of demand-pull and technology-push instruments. They have a high internal technological capability and combine internal and external information sources, mostly in cooperation with knowledge institutions. Environmental innovators are more concentrated in mature, traditionally highly polluting sectors, but new firms are not more environmentally innovative than incumbents. Most importantly, in contrast to other environmental innovation studies, mostly carried out in a German context, we have not found evidence of a market pull from either the domestic or international markets. Furthermore, cost savings are not found to be a distinctive driver for environmental innovators. These differential results are possibly related to the special features of Spain regarding its national innovation system and the degree of stringency of environmental regulation and environmental consciousness of its consumers. Copyright © 2013 John Wiley & Sons, Ltd and ERP Environment.