Trade unions are facing a decrease in the formal adhesion rate, a situation that is multi-causal, but among these various actors, leadership could be one of the most relevant variables. The aim of this paper is to analyze the perception about the transactional and transformational leadership styles of the union and guild leaders of the Los Lagos region, Chile. In order to achieve this purpose, a sample of 28 leaders was studied, to whom an instrument based on the adaptation of the multifactorial leadership questionnaire MLQ developed by Bass and Avolio was applied, adapted to the Chilean organizational context. It is made up of new items and psychometrics properties, in terms of capacity for discrimination, reliability and validity In this research, a set of information was obtained, and allows to get a vision of the leaders through their self-perception. The Cronbach alpha coefficient obtained was 0.8560 for the questionnaire, which indicates a good reliability of the scale.