A three-stage professional development (TSPD) model for training experienced teachers to become teachers' leaders is presented here, along with a study assessing its value. The three stages of the model are: a "basic training" stage, a "master-teacher" stage, and an "independent implementation" stage. This qualitative study included open questionnaires and interviews of participants and course leader after the various stages. Statements were classified accordingly to three main themes: "teachers as pedagogues," "teachers involvement in environmental science (ES) community," and "teachers as leaders." Results show that participating in the TSPD course enabled teachers to unify into one coherent community with similar goals, increased their self-confidence, empowered them as teachers by improving classroom function, and intensified their abilities to act as teachers? leaders. This model, although tested on environmental science teachers, is applicable to any teacher community.