The focus of this article is on the personality of a social worker as most qualified representative of the profession. The task of the article is to explore social worker’s personal agency and context beliefs as a factor to increase the motivation of social worker’s professional activity. The methodological basis of the research is the Concept of Effective Functioning (Motivational Systems Theory, Ford, 1992). The talk – interview was used to gain factual information about social worker’s capability beliefs related to the main elements of problem solving process. To explore social worker’s context beliefs, a construct embracing essential factors characteristic to social organizations was made. The research provide information about the mentioned parameters of the beliefs and reveal the dominating patterns of social workers’ professional functioning indicating the level of their motivation.