This study explored factors contributing to job satisfaction and dissatisfaction of male and female Iranian secondary school English teachers. A Likert-scale 58-item questionnaire was developed which was completed by 210 participants. The questionnaire also included three open-ended questions which investigated participants' motivation and demotivation and required them to suggest ways to address the demotivating factors and improve their job satisfaction. The most teacher motivating factors were found to be (a) imparting knowledge to others, (b) serving the society and (c) having an internal desire to teach. However, analysing the data obtained from the Likert-scale questionnaire and considering the participants' responses to open-ended questions as well as their comments during a focus-group interview, we found that the most demotivating factors contributing to Iranian secondary school English teachers' job dissatisfaction included (a) inadequate salary, (b) principals' inattention to the teachers, (c) not being encouraged to seek professional development, (d) students' lack of motivation to learn English, (e) low occupational and social status. Furthermore, slight differences were found between male and female teachers in relation to factors contributing to their job satisfaction/dissatisfaction.