PurposeThe purpose of this paper is to shed light on the relationship between organizational commitment (OC) and organizational citizenship behavior (OCB) as mediated by employee engagement (EE). The impact of different facets of OC (affective, continuance and normative) and EE (alignment, affectiveness and action-orientation) is examined with respect to OCB.Design/methodology/approachInsights from the literature underpin the hypotheses on how EE mediates the relationship between OC and OCB. Primary data using survey questionnaire were collected from 881 permanent employees of Delhi Metro Rail Corporation (DMRC) in India. Hayes' model 4 has been used for the mediation analysis.FindingsThe analyses show that only one facet of OC- affective commitment and the alignment and action-orientation dimensions of EE positively affect OCB. The relationship between OC and OCB is fully mediated by EE.Practical implicationsThe results imply that engaging employees is pivotal for effectively fostering citizenship behavior among employees. Organizations should be willing to implement strategies and interventions which enhance the emotional experience of employees to foster a sense of belongingness with the organization and engage them.Originality/valueThe paper draws on a unique data set of a prestigious organization in India to provide insights with substantial degree of generalizability into the relationship between OC, OCB and EE, whilst applying a comprehensive definition of these constructs. It is the first study to examine the inter-relationship among different facets of these constructs.