This paper describes the history of the International Society of Physical and Rehabilitation Medicine (ISPRM). Past achievements and current challenges are outlined. ISPRM has been successful in setting up a central office, attracting individual and national members, holding international congresses, and establishing relations with the Journal of Rehabilitation Medicine (JRM) as the organization's official journal. ISPRM is currently in official relations with the World Health Organization (WHO) and collaborates closely with WHO's Disability and Rehabilitation team. ISPRM, however, also faces challenges with regard to its growth and the realization of its goals. These include boundaries of voluntary leadership, limited economic resources, the need for enhancing the central office, variations in membership, limits of the current congress bidding system and structure, relations with regional societies, and the need to further develop policies within the field of Physical and Rehabilitation Medicine (PRM) and in relation to WHO and the United Nations system. It is concluded that ISPRM must evolve from an organization, of which the main activities are to hold a biennial congress hosted by a member nation and to provide input to WHO on request, into a professional non-governmental organization (NGO). ISPRM should embark on assuming a leadership role in the further development of PRM within the broader area of human functioning and rehabilitation.