Parents are real beneficiaries of school services. Their involvement in school based activities has changed the role breadth of teachers. Schools can handle this parental involvement through the extra-role behaviors of teachers. These beyond the job behaviors or organizational citizenship behaviors (OCB) of teachers are crucial for the schools. Despite the prescribed roles and duties, the schools cannot predict and infer through formally stated in-role job description, the entire range of extra-role behavior exhibited by teachers during and after school. In this study, teacher's role breadth is examined under the broad spectrum of Organizational Citizenship Behavior (OCB) which resulted into a conceptual model on the determinants of teacher's OCB. A qualitative evaluation (grounded theory) of 40 interviews has been conducted with all the stakeholders of school in India viz., principals, fellow-teachers, students, and parents. The most striking finding is that teachers are displaying prosocial behavior. Teacher's OCB is found to have three determinants-OCB-Individual, OCB-Organization and OCB-Prosocial. Involvement of parents in school are redesigning and affecting the actions of teacher. Further, the implications and directions for future research have also been discussed.