Startups are innovative companies that live in uncertain environments. This research aims to characterize the conditions and variables that influence the development of startups in the context of the Brazilian economy, so that understanding is reached about the characteristics of their businesses and how the environment acts on them. An evaluation instrument is developed that assists in the validation of critical factors, as well as the KPIs necessary for the practice of the instrument. The study presents, through bibliographic research, a theoretical proposal of critical success factors that receive the assessment of stakeholders who are in daily contact with the reality of startups. The results demonstrate the impact of critical success factors on the development of startups, according to the perception of stakeholders.