Teachers have to face many different stressful situations in schools. In this context serious attention
has been paid, and much research has been carried out, to investigate the issue of potential stressors
occurring in school or class environment. Although pre-service teacher training does not usually
include training related to the development of the teachers` competence to solve stressful situations
in lessons, as soon as teachers start their teaching career, they are automatically considered to be
equipped with this competence. In the research, presented in this paper, the main goal was to identify
the most frequent stressors that primary and secondary school teachers face in their everyday
teaching. Two methods were used to collect necessary research data: a semi-structured interview
with teachers, and observation of teachers during the lessons they taught. Based on the interview
data analyses the following nine stressors were identified as the most frequent and most serious (in
order): difficult students, mismatch between students’ performance requirements and their abilities,
disruptive behavior of students, inadequate student attention, social and emotional factors of the
environment in which students live, use of mobile phones during lessons, overwork and fatigue of
teachers, insufficient school equipment and lack of teaching aids, conflicts among students. The aim
of the observation was to confirm in practice, the types of the stressors identified from the interview
data. Analysis of the records from observations, confirmed some of the previously (in interviews)
identified stressors and also identified some further stressors.