The title of the Török Ignác Secondary School’s application was 'Learning by Teaching - Teaching by Learning'. Emphasized objective of our institution was to study the international experience of mentoring candidate teachers and teacher trainees. These are relatively new tasks in our school. Being an institution of reference, our goal is to become a training school for univerisities and colleges. We intend to regularly receive graduate students majoring in teaching for their consecutive, 2-semester long individual teacher training practice. This activity has been occasional so far, primarily our ex students applied to spend their teaching practice in our school (a few weeks or maximum 4 months). However, based on our accumulated pedagogical experience and good regional position, it can rightfully be counted on that more and more graduates are going to accomplish their school year long teaching practice in our school. The mentoring process of teacher trainee classification and preparation for the trainees' obligatory qualifying exam (both introduced recently) are also new challanges. In our teaching staff 5 people have already acquired specialist mentor teacher qualifications, some teachers have accomplished shorter mentoring teacher training courses. In addition to this, there are other colleagues in our staff who intend to take part in helping candidate teachers and trainees. Within the framework of Erasmus+ we were planning to visit foreign teacher training institutions where the mentoring system could be examined in progress. We contacted teacher training institutions with effective help of our German and Dutch partner schools. In the United Kingdom our partner was directly the Teacher Training Institution of the University of Bristol. During their 1-week job shadowing visits, altogether 9 colleagues acquired knowledge about the local structures, had a sight into how they work, had a chance to take part in sessions and discussions which supported teacher trainees and candidate teachers. Basic aspects for choosing participants of the field trips were aptitude for the mentoring activity, open personality and alongside with appropriate language competence, the even distribution of subjects. 2 colleagues received highly appropriate and vital knowledge concerning teacher mentoring activities by taking part in 2-week teacher training courses in the United Kingdom. Accomplishment of the project objectives has contributed to performing our mentoring tasks at a higher level, instantly as well as in the long run. The colleagues who took part in the mobilities could use their experiences right after their return to teaching. After their reports to the fellow teachers and the trainings they held, other colleagues aspired for Erasmus+ teacher training courses in the UK in a new project, which help to revitalize our teaching activities.