The success of any school depends among others on the social capital including teachers, students, parents and other stakeholders who support the business of imparting knowledge. Satisfied and committed teachers impact both on individual student performance and general academic standards of the school. The study explored job satisfaction among primary school teachers in relation to certain demographic variables. The objective of this study was therefore to examine the influence of demographic factors on job satisfaction of teachers in public primary schools in Bomet County, Kenya. This was done by conducting a survey using a self-administered questionnaire. A total of 848 teachers in 129 primary schools participated in the study. Descriptive and Inferential statistics were used to analyze the data. The overall finding was that teachers were ambivalent on job satisfaction, meaning that they were not sure whether they are satisfied with their jobs. However, teachers were satisfied with their colleague co-teachers and happy when assigned administrative duties. Teachers were more satisfied when authority was delegated to them. It is evident that school leadership needs to improve in ways of supervision, systems of reward, ways of communication, and working conditions. It was further established that there was significant differences in the level of satisfaction of male and female teachers for satisfaction with administrative duties (t = 2.645) and satisfaction with teaching (t = 2.448). It was also found that male teachers are more satisfied with administrative duties (m = 3.2; s.d. = 1.05) than female teachers (m = 2.91; s.d. = 1.18). Similarly, male teaches are more satisfied with teaching (m = 2.6; s.d. = 0.70) than female teachers (m = 2.5; s.d. = 0.79). This implies that female teachers are not keen on taking up additional administrative duties in the school. Overall, there was no significant difference between the levels of job satisfaction between male and female teachers. On the other hand, it was found that job satisfaction was positively correlated with the "age of respondent" (r = 0.092; p<0.01) and "experience in teaching" (r = 0.081; p<0.05).