Achieving sustainable development is one of the most significant challenges facing humanity globally in the 21st century. The sustainable development of society is linked to education through the seventeen goals of sustainable development approved by the member countries of the United Nations in 2015. Thus, it has a key role in building competences for sustainable development by providing the knowledge and skills needed to address contemporary global challenges and promote sustainable lifestyles.

Teachers, as leading figures in the educational process, are essential for the formation of these competencies in students. Their professional qualification related to the successful formation of competence for sustainable development requires them to be familiar with new educational methods and current scientific research in order to effectively prepare their students for their future roles as conscientious and active citizens.

A team of researchers from the University of Plovdiv (Bulgaria) undertook an experimental study of the readiness of Bulgarian teachers to integrate the ideas of sustainable development into the learning process through an integral approach in order to form competence for sustainable development in students. A questionnaire was filled out by a number of teachers from primary and secondary schools from the city of Plovdiv. The article describes its results and the conclusions drawn. Some of them have a general nature and do not only apply to Bulgarian teachers. Based on the summaries, the authors also share their vision for optimizing the in-service training of teachers in the direction of understanding the role and possibilities of the integral approach in education for sustainable development.

Keywords: Education, key competences, sustainable development.