This study presents part of a research project currently underway which aims to characterise the best practices of highly effective schools in the Autonomous Region of the Basque Country (Spain). Multilevel statistical modelling and hierarchical linear models were used to select 32 highly effective schools, with highly effective being taken to mean any school with higher-than-expected student results after adjusting for the effect of contextual factors. Subsequently, qualitative techniques were used to record the perceptions of the management teams, educational advisors and inspectors of the selected schools regarding the practices in place in their organisations. This paper presents the results obtained in relation to leadership. These results indicate that leadership comprises a number of different competences that are manifested to different extents in the different schools, although a set of elements was identified as being common to the majority, namely: positive leadership in the school management, a clearly defined mission shared by all professionals, a positive attitude to training and lifelong learning, the ability to foster the commitment and motivation of the teaching staff in relation to a common school project, support for teaching and learning processes, attention paid to questions of peaceful and harmonious coexistence and well-organised coordination.