Studies on students' motivation to learn Chemistry in developed countries are largely common in the literature. However, very few studies have been carried out with a view to investigating students' motivation to learn Chemistry in places like Latin America, and specifically in Brazil. The present study sought to translate the Chemistry Motivation Questionnaire II (CMQ-II) with a view to evaluating the motivation to learn Chemistry among Brazilian high school students. The study was conducted using responses obtained from 510 high school students who completed the CMQ-II during the COVID-19 pandemic. Exploratory factor analysis, confirmatory factor analysis and analysis of model invariance between genders were carried out in order to compare the results obtained with those of the other studies conducted using the CMQ-II. The results obtained from this investigation showed that the CMQII had a five-factor structure with factor loadings [greater than or equal to] 0.52 and Cronbach's [alpha] [greater than or equal to] 0.81. Multivariate analysis was also carried out with respect to gender differences, and the results obtained showed that Brazilian boys had higher confidence when it comes to learning Chemistry, while the girls mostly studied Chemistry to obtain a good grade or because of the importance of the discipline in their imagined future career. The findings show that the Brazilian version of CMQ-II applied in this study seems to provide a consistent scale of analysis compared to that reported in the literature.