This paper examines facets of the developing business relations between two important actors in the supply-chain of transnational healthcare: medical tourism facilitators and medical doctors (MDs) practicing privately and internationalising their services. The empirical focus is Greece, an emerging destination for medical care. Drawing on the sociology of the professions as an analytical framework, rich qualitative data reveals a conflictual aspect in the relation between the two actors, and informs the literature on transnational healthcare of barriers to market development. Particularly, MDs practicing privately often resist what is perceived to be medical tourism facilitators' pressures to control the 'rules of the game' in the submarket which inhibits their collaboration. The paper contributes, thus, to the sociology of the professions by bringing to light a new challenge for MDs engaged in the transnational business arena, represented here by the facilitators; and encourages tourism practitioners to consider MDs' self-understanding, attitudes, and expectations