This paper deals with sources of stress at the work of kindergarten teachers in the kindergartens of the city of Zagreb. In order to better understand the problem and enable timely prevention, the theoretical part defines the concept of stress, the type of stress, the causes of stress at the workplace, and an overview of the current stress research. In the course of the paper, a study was carried out to investigate different sources of stress on the work of kindergartens in kindergartens in Zagreb. The study involved 257 preschool teachers from Zagreb in the age of 22 to 65. It was found that 61.8% of respondents were satisfied with the job, but 45.9% considered their work very stressful. For the purposes of research, Scale of Assessment of Stress on the Work of the Educator was used. The scale describes the everyday situations that the educators encounter and have to assess the intensity of stress, or to what extent, the stressful situation in the job is determined. Research has shown that the greatest intensity of stress among the educators is causing situations with the superiors, the professional service and the parents. Also, 59.9% of educators given opportunity, would to change their job. Research results contribute to better understanding of the work of educators and the sources of stress. They help in further developing detection, prevention and resolution measures.