In addition to providing students with the necessary knowledge, teachers have an important role in education that is vital for the success of their schools. Lately, the topic related to stress among teachers which stems from the ludicrous expectation given to teachers has become a hotly debated topic and discussion in Malaysia. Apart from being given high expectations, teachers are also not provided with sufficient and suitable resources to facilitate them in carrying out and completing their work. Accordingly, this research was conducted to see if job demand and job resources have a significant relationship with stress among teachers in Klang Valley. Results show that both job demand and job resources have a significant relationship with stress with P-value=0.000. In addition to the correlation analysis, this research also proved empirically that job demand is the cause of stress among school teachers with P-value=0.000 and T-value=14.901. Moreover, from the results, it can be concluded that there is no difference in opinion between male and female teachers about job demand, job resources, and stress in schools in the Klang Valley. Because teachers' stress is closely related to schools' performance, this research was conducted with the hope that the research results can be used as a reference for schools' leaders (i.e., headmasters/headmistresses) in the efforts to improve the performance and quality of schools in Malaysia. The effort is believed important as it will indirectly help Malaysia not just towards the attainment of its National Education Policy's (NEP) goals (to ensure a robust and responsive education system via quality -instruction, mentoring and support to students) but the sustainable development goals too (SDG4 -ensuring inclusive and equitable quality education) that are highly depending on the school teachers.