This project is a five-year leadership development project in mathematics educaton that addresses the need to retain qualified mathematics teachers in the profession. The primary goal is to keep competent beginning and experienced K-12 teachers in the profession while increasing their ability to teach mathematics effectively. The project is based at the University of Califonria, Santa Barbara, and involves teachers and districts in Ventura and Santa Barbara counties. In Project RENEW, two cohorts of 30 experienced teachers will received 36 days of professional development over a three-year period. These teachers, called preceptors, will increase their knowledge of mathematics and mathematics pedagogy, develop their leadership capabilities, and develop and implement strategies to mentor three to five beginning teachers for a period of three years. The plan is to involve the two cohorts of 30 teachers with two cohorts of 120 beginning teachers for a total of 300 teachers. A resource manual for devloping teacher leadership for mentoring beginning teachers will be developed.