We explore whether environmental motivation affects environmental behavior by focusing on volunteering. The paper first introduces a theoretical model of volunteering in environmental organizations. In a next step, it tests the hypothesis working a large micro data set covering 32 countries from both Western and Eastern Europe using several different proxies to measure environmental motivation. As a robustness test we also explore the relationship at the macro level extending the number of countries investigated. Our results indicate a strong positive relationship between environmental motivation and individuals’ voluntary engagement in environmental organizations.