Dissertation (MA Education)The study aimed to assess the effects of stress on Secondary School Teachers‘ job performance in Sumbawanga Municipality in Tanzania. Specific objectives of the study were: to identify sources of teachers stress in secondary school at Sumbawanga Municipality, to determine effects of teachers stress in secondary school at Sumbawanga Municipality and to examine coping strategies used by teachers in secondary schools to overcome stress at Sumbawanga Municipality. The study was guided by Transactional or Cognitive Theory of Psychological Stress and Coping. This theory based on sources, effects and different coping strategies which can be applied by teachers to reduce or remove the stress. Both quantitative and qualitative approaches were applied. The study employed purposive sampling and simple random sampling procedure to get 73 respondents, whereby 66 respondents were secondary school teachers, 6 of them were heads of school and 1 Municipal secondary education officer. Numerical data were analyzed by descriptive statistics and the qualitative one was subjected to content analysis. Data collected were analyzed by using Statistical Package for Social Sciences (SPSS) version 20. Methods that were used for collecting data were documentary review, interviews and questionnaires. The findings revealed that low salary, poor teaching conditions and work related stress are common stressors to teachers. Also, findings revealed that, low morale, absenteeism as well as teachers‘ turnover are the major effects of stress in secondary school teachers. On the other hand the findings of the study showed that, teachers cope with stress through prayers, counseling, doing physical exercise and learn techniques of relaxation