This article reports on a study the aim of which was to sketch a tentative model for illuminating variations in the professional role of a social worker, based on Swedish social work students' own experiences of knowledge use and its premises in client meetings during field practice. Social work students voluntarily submitted narratives depicting problematic and unproblematic situations experienced during field practice in one of three broad occupational positions of social work: casework; counselling; and social assistance. Three different formative aspects were identified as constituting premises for knowledge use in social work. Knowledge use from differing epistemological domains are set in relation to the identified formative aspects, all together comprising a role that we label 'the Compassionate Bureaucrat'.