This systematic literature review (SLR) identifies and ranks the decisions that can be considered critical for entrepreneurs at the early stage of the start-up process. The sample (N = 45) derived from the SLR contained primary publications from the A + and A journals of the VHB-Journal ranking. Deductive and inductive approaches were used to define the critical decision domains. Then, the relevance of the domains was evaluated using the frequency of the selected studies. A key implication for founders is to understand that not all decisions that could be taken in the early stage may be critical for success. Most critical seems to invest time and effort in the, what we label the internal business and human core (Product Definition and Core People) and the external business and human core (Market segment selection and Partnerships). This study depicts an integrated view of the fragmented field of critical decisions in the context of early-stage start-ups by using a SLR. Thus, it creates value for theory-building and practitioners in entrepreneurship.