Reports on drop-out rates and difficulties experienced by beginning teachers require an examination of the motivational processes that characterize teachers at this stage. Support systems for beginning teachers in the induction period in Israel include a workshop and a mentoring process. This study examined how support in beginning teachers' psychological needs by workshop facilitators and teacher-mentors in schools contributed to their optimal functioning in workshops, schools, and in teaching. Questionnaires were administered to 261 Bedouin Arab and Jewish beginning teachers. Based on structural equation modeling analysis, results indicated that support in teachers' needs by workshop facilitators predicted a sense of competence and autonomous motivation in the workshops, which in turn predicted autonomous motivation in teaching. Autonomous motivation in teaching was also predicted by the teacher-mentors' support and in turn predicted teachers' sense of competence, investment in the school, and sense of self-actualization. The findings have implications regarding the conditions needed to improve the functioning of beginning teachers of various cultural groups and highlight the importance of an environment that supports teachers' needs during their induction.