Research relevance is determined by the need to enhance teacher education, consolidate teachers' further professional and personal development, increase the prestige of the teaching profession. The article focuses on enhancing professional training of teachers in the European countries under the conditions of lifelong learning. Based on the study and analysis of researches by Ukrainian and foreign scholars and some statistical information, the peculiarities of teaching and teacher training have been justified. Mentoring has been described as a way of transferring experience, knowledge, abilities and skills from one age group to another, or from one person to another. It has been found that mentoring aims to provide support and promote self-realization in professional activity. Lifelong learning has been defined as a programme for thinking and activity development. The statistical data on the needs of teacher development and thematic demand and supply in lifelong learning have been analyzed. It has been emphasized that modern trends in the development of lifelong learning for teachers in the EU countries include consolidation and rationalization of organizational structures with the purpose of developing the national systems of postgraduate teacher education based on scientific principles of organization and management theory, as well as orientation towards reaching the balance between the interests of all participants, partners, central authorities of education management, regional and local education authorities, school administration, teachers; stimulating innovative activities of teachers, etc. It has been concluded that taking into account European experience in organizing lifelong learning for teachers will allow Ukraine to enhance professional training of teachers, professionalization in self-education, their reflexive practice of searching for effective ways to integrate the latest technologies into the education process.