Organizational Citizenship Behavior (OCB) is one of the keys to the success of an organization. This current research aims to evaluate the effect of Professional Commitment on Kindergarten teachers' OCB. This quantitative research applies a cross-sectional survey design with an explanatory research type, with 145 Kindergarten teachers as the research subjects. The results show that Professional Commitment significantly affects OCB by 70.6%. In addition, teachers with higher Professional Commitment possess higher OCB in carrying out their professional duties. The results also show that the dimensions of Affective Professional commitment, Normative Professional commitment, and Continuance Professional commitment significantly affect the OCB of Kindergarten teachers.