Academic spin-offs are companies created to exploit some of the intellectual property developed within universities. When they are founded by the inventors themselves, who are linked to the career of the higher teaching profession, it is possible to observe that in most cases the business activity is carried out on a part-time basis and in a nearby place or even within the universities, to facilitate conciliation with the teaching career (SHANE, 2004). In this double journey the teacher faces two complex and challenging activities: teaching and entrepreneurship. Considering career as an evolutionary sequence of a person's work experiences over time (ARTHUR; HALL; LAWRENCE, 1989, p.8), this article aims to analyze the career trajectories of teachers, who have developed technologies within Brazilian and Portuguese universities and chose to take them to the market through the creation of Spin-offs. The intention is to understand the factors that motivated the choices of these professionals, the main facilitators and obstacles encountered by the teachers, as well as the contextual differences, since it is a comparative study between Brazil and Portugal. This debate is based on a wide discussion in the literature about career trajectories and their classification as traditional or non-traditional, according to the type of employment-employer relationship, reasons for choosing the desired career (remuneration, stability, personal values), as well as aspects such as the investment in learning and self-development (ARTHUR, ROUSSEAU, 1996, MAULLERO, SULLIVAN, 2006, DUTRA, 2010, VELOSO, 2012). In order to achieve the intended objective, semi-structured interviews were conducted with professors linked to Brazilian and Portuguese universities, in which aspects related to the career trajectory of the researchers who founded their spin-offs were addressed, including aspects such as: decision by the creation the work of the teacher and the entrepreneur, as well as the incentives and difficulties experienced, considered the main categories of analysis adopted. Each one of these categories was codified and organized, generating a structured hierarchy, which supported the interpretations and analyzes made, according Barbour (2009). In conclusion, the results indicate that the career trajectory of teachers who deal with Spinoff is impacted by several factors, among them: the stage of the career cycle, interest in spreading the technology and bringing it to practice, interest (SHANE, 2004, HAYTER, 2010) and the search for more challenging activities (KILIMNIK, 2011). These results reveal the importance of understanding the career trajectories of these professionals, regarding the facilities and challenges faced during the conciliation of academic activities and entrepreneurship, in the two countries investigated, contributing to the debate on contemporary careers, as they can. be built in the academic environment and how they can be encouraged.