Healthcare chaplains operate in many healthcare sites internationally and yet their contribution is not always clearly understood by medical and healthcare staff. This review aims to explore the chaplains’ role in healthcare, with a view to informing best practice in future healthcare chaplaincy. Overall the extent of the provision and staffing of chaplaincy service internationally is unclear. From this review, several key spiritual and pastoral roles in healthcare emerge including a potential contribution to ethical decision making at the end of life. Healthcare chaplains are key personnel, already employed in many healthcare organizations, who are in a pivotal position to contribute to future developments of faith-based care, faith-sensitive pastoral, and spiritual care provision. They also have a new and evolving role in ethical support of patient, families and healthcare teams.