As service firms face intense pressure to improve service quality, contact employees have been asked to do more with less. It is important that managers understand the concept of organisational citizenship behaviours and attempt to motivate employees to exhibit such behaviours. This study developed and tested a model of how employees' perception of organisational support affects affective commitment (AC), which contributes to their citizenship behaviours in service settings. Questionnaire data from matched pairs of 318 contact employees and their supervisors demonstrated that both perceived organisational support (POS) and AC play strong, central roles in determining contact employees' exhibition of citizenship behaviours. In addition, AC was found to be an effective mediator linking contact employees' perception of organisational support to their citizenship behaviours.