Student outcomes of Education for Sustainable Development (ESD) is reported to be weak and empirical studies investigating the underlying causes have been called for. School organization is pointed out as essential, which highlights the role of school leaders in realizing ESD. This study aims to identify characteristic features of ESD active school organizations, by investigating how school leaders maintain high quality in their organizations. ESD is thus studied from an internal organizational perspective. Fourteen school leaders at ten upper secondary schools, active in ESD implementation, were interviewed and qualitative data quantified. A special focus was on school leaders’ transformative statements, in response to earlier criticism that ESD implementation has been too structural. Results consist of 26 identified quality criteria. By means of cluster analysis, the quality criteria were merged into four principal quality criteria: collaborative interaction and school development, student-centred education, cooperation with local society and proactive leadership and continuity. The school leaders’ quality strategies were identified through correlation analysis of their principal quality criteria. The quality strategies reveal a difference in the schools’ internal or external focus. An analysis of the school leaders’ quality statements in relation to their quality strategy implementation indicates that ESD to a large degree is introduced from a transformative perspective. One school in the study stands out as highly transformation-oriented, and has a quality strategy combining an internal and external focus, thus making it a possible benchmark for successful ESD-implementation. The study contributes a suggestion on how a progression of ESD implementation can take place and as well as possible obstacles. / Studier om implementering av Lärande för hållbar utveckling (LHU) visar att påverkan på elevers förståelse, attityder och agerande i frågan är liten. Det finns ett behov av att empiriskt undersöka hur skolans organisation kan underlätta en mer framgångsrik LHU implementering. Rektorernas roll pekas ut som central i det arbetet, men få studier har tidigare undersökt hur rektorer arbetar med skolorganisationen. I studien undersöks generella uttryck för kvalitet som rektorer anser viktiga i skolorganisationen för att åstadkomma en utbildning med hög kvalitet. Resultaten tolkas i ljuset av skolor som aktivt implementerar LHU. Studien söker svar på vad som utmärker de skolorganisationer som aktivt arbetar med LHU. 14 rektorer på 10 LHU-skolor har intervjuats. Kvalitativ data har kvantifierats i syfte att upptäcka mönster och sammanhang. Ett speciellt fokus har ägnats åt transforamtiva uttryck, som ett svar på tidigare kritik mot att LHU implementerats allt för strukturellt inom skolan. Resultaten redovisar kvalitetskriterier som rektorerna framhåller som viktiga samt specifika fokusområden för kvalitetsarbete. Skolor i studien med hög medvetenhet om transformativa uttryck inom skolans organisation utgör grund för en diskussion om hur strategier för LHU implementering kan utformas.