While research on education for sustainable development (ESD) is expanding, empirical evidence on its impact and outcomes remains very limited. Moreover, the facilitating role of the school organization, while extensively documented in literature on school management and school effectiveness, is lacking. In this study we present and qualitatively validate a framework for an ESD-effective school, previously developed via a critical review of ESD and school management literature. This framework consists of eight characteristics: sustainable leadership, school resources, pluralistic communication, supportive relations, collective efficacy, adaptability, democratic decision-making and shared vision. Via semi-structured interviews, the framework for an ESD-effective school was theoretically validated via a sample of 19 teachers and school leaders with expertise in ESD. The findings from the interviews show that the participants largely confirm the framework and the individual characteristics are recognized by the sample. There were relevant differences between the respondents in terms of positioning the different characteristics within the framework. Specifically, views on pluralistic communication differed from the initial conceptual framework.