Abstract
The aim of this paper is to give an overview of the phenomenon of professionalization that is observable in organizations from the nonprofit sector. Empirical research was conducted among Hungarian nonprofit organizations, and the data were collected within the framework of a country-wide survey. Through the analysis of the research results, the paper provides deeper insights into knowledge about professionalization trends in the nonprofit sector. It proves that organizational development positively impacts nonprofit organizations’ improvement of their professionalization level and the members of these organizations.