The aim of this research was to identify the critical competence of success of the commercial adviser in a company providing insurance and health services. For this research a sample of 34 commercial advisers. The sample was divided into four groups (two per product and two per criterion of success). Systematic fi eld observations, interviews of critical incidents, application of response tests and sales workshops were used to evaluate the differential competences that the successful advisers were showing in relation to the advisers de fi ned as average. The success criteria were based on the generated commission performance over the 10 months. All in all, signi fi cant differences were found between the “successful” and “average” groups. Furthermore, competences that correlate positively with a top sales performance were observed and competences that have major level of discrimination between the “successful” and “average” groups were established. Orientation to achievement, planning and management, information search, commercial aggressiveness and strategic vision are the competences that were considered to be key in the top performance of a sales agent or commercial adviser. Additionally, the results in the response tests were analyzed in the four study groups, without observing signi fi cant differences between them, which supports the theoretical framework of the present study.