Start-ups are an attractive topic for research because they are a relatively new and very dynamic business form. They carry out original business ideas, provide a space for self-realization of independent personalities, bring extra earnings, but most of them fail. The aim of the research was to examine whether the business model and start-up team like two basic assumptions are really some reasons of the viability and later potential start-up success. The result of the research is a knowledge on the structure and functionality of the start-up business model and start-up team. The viability of the start-up had been measured in shape of its business performance. An intensity and structure of the relationships between performance of start-up and its business model and team should confirm its capability to survive and thrive. These relationships are modelled on the base of regression analysis. The research has largely confirmed the existence of desired relationships to a certain extent, but the effect of the studied preconditions is internally considerably differentiated.