This article is the result of the authors’ scientific interests as presented in numerous earlier studies and publications concerning entrepreneurship, which are, in large part, interdisciplinary and combine management science and psychology. The construct of entrepreneurial success provides entrepreneurship with actual significance when considering that entrepreneurs’ failures carry no major positive aspects. Furthermore, because researchers and entrepreneurs define this phenomenon differently, the understanding of entrepreneurial success is quite diversified. Hence, there no tool exists in the literature that comprehensively describes and measures entrepreneurial success. Such a complex tool that both enriches scientific knowledge and allows the reliable and objective measurement of entrepreneurial success, while taking into consideration economic-financial and subjective elements, may be useful in practice, such as when evaluating an entrepreneur’s request for business development credit or when encouraging an investor to cooperate. It would be risky to base such serious decisions solely on economic-financial measures (e.g., if a company is earning profits but the entrepreneur neither feels confident nor derives satisfaction from the business, is the company’s situation stable?) or exclusively on the entrepreneur’s subjective perception (e.g., if the entrepreneur is confident in his abilities and foresees a bright future for his company but is incapable of controlling the costs and analyzing the market, are his expectations for profits realistic?). The objective of this article is to report on the initial stage of construction of a new tool – the Questionnaire of Entrepreneurial Success. A description of the research procedures with an emphasis on the tools, a presentation of the findings and the conclusion of the results follows the literature review.