The study was spurred by the excessive stress among teachers and its attendant negative consequences and as such investigated the sources of stress and its management modalities among teachers in secondary schools in Rivers State, Nigeria. The study answered three research questions and tested three corresponding null hypotheses. The analytic descriptive survey was the design for the study. The population of the study comprised all the 7,142 (3,681 males and 3,461 females) teachers in the 274 public secondary schools in Rivers State. The sample size of the study was 714 (368 males and 346 females) teachers chosen through proportionate random sampling technique. Stress and Management Modalities Scale (SMMS) was used for data collection. Face and content validities were determined by experts in the areas of Educational Psychology and Test and Measurement. The internal consistency through Cronbach alpha gave the reliability coefficient of SMMS to be 0.83. Mean and standard deviation were used to answer the research questions while z-test was used to test the hypotheses. It was found that the sources of stress are distance to schools, overtime, hostile environment, excessive workload and pressure of work, family challenges, paltry salary and poor emotional state. The types of stress experienced by teachers are acute stress, fear-based stress, work - load stress, job adjustment stress, time management stress, and physiological stress. It was recommended that teachers in public secondary schools should device a coping strategy for any problem that they cannot immediately solve in order to avoid unnecessary pressure. The teachers should endeavour to know when they are stressed to take a recreation where necessary.