Organisational citizenship behaviour (OCB) is an evolving concept concerning how and why people contribute positively to their organisations beyond defined work roles that have rapidly expanded in recent years. The study of OCB engages fundamental questions analysing the circumstances in which individuals “go the extra mile” in the workplace. This briefing reviews the literature to shed a light on the antecedents and enabling environments for OCB in order to improve employee and employer ability to maximise citizenship behaviour for mutual benefit.