This study is a causal study to examines the influence of mastery experiences, vicarious experiences, social persuasion, physical and emotional states, stress, optimism, job satisfaction and teaching duration on teaching efficacy of Islamic Studies (IS) teachers. A total of 55 IS teachers were recruited using random sampling from several regions in Jakarta and South Tangerang. Confirmatory factor analysis was conducted to assess the dimensionality of each scale. Multiple regression was used to analyses the data. Results indicated that mastery experiences factors, social persuasion and optimism significantly influence teaching efficacy of IS teachers, while vicarious experiences, stress, job satisfaction, physiological and emotional state and the teaching duration do not significantly influence teaching efficacy of IS teachers. It is suggested that the schools or the parents often give rewards or appreciation to IS teachers, so they will have a high self-efficacy in performing their tasks. Schools should always carry out training for improving professional, pedagogical, personality and social competencies of the teachers. With this training, teachers will become more professional and always successful in teaching, so that the successful experiences can enhance their self-efficacy. To keep the conducive teaching environment and to support the learning and teaching process, the IS teachers should be always optimistic of their success in teaching the students properly