Ecosystem disservices (EDS) highlight the negative effects of nature on human well-being. Like ecosystem services (ES), EDS impact economic and non-economic aspects of human life within social-ecological systems (SES). The concept of EDS has been much debated, with strongly differing opinions regarding its utility and implications. In this opinion paper, we emphasize its relevance and complementarity to the ES concept for analyzing SES, and advocate applying EDS to SES research more systematically. Firstly, we highlight that though EDS are now sometimes studied, they remain neglected compared to ES. Secondly, we propose five reasons why EDS and ES are complementary concepts. Thirdly, we suggest that EDS are critical to understanding stakeholders’ behavior regarding ecosystems. Drawing on existing studies, we illustrate how stakeholders in SES simultaneously perceive and benefit or suffer from ES and EDS. We further suggest that, under certain conditions, EDS may influence people’s behavior more than ES. Such 'EDS-biased behavior' implies that, under certain circumstances, targeting EDS reduction may be more effective than targeting ES increase to encourage nature-friendly behaviors. Finally, we provide five recommendations to further integrate ES and EDS in research, as a pathway towards improving the understanding of SES and the effectiveness of sustainability policies.