The article examines the ethical basis of professionalism as one of the most important characteristics of personal development. According to the authors' opinion it is professionalism that ensures the individual's ability of productive, creative work. The authors analyze correspondence between the concepts "professionalism" and "professional" and give axiological and acmeological understanding of professionalism. A phenomenon of professionalism in the history of mankind extended following the sophistication of the social structure, when new conditions for the one's self-actualization were arising and one's attitude to labor and its components were changing. The historical path traversed by the concept of professionalism resulted in the fact that nowadays it is a multi-aspect phenomenon. Nowadays the individual's ethical values and priorities that allow one to choose the optimal format for professional duties execution, along with the corresponding knowledge, skills and abilities, become the basis of professionalism.