This article presents the evolution of overweight and obesity among Québec adults from 1990 to 2004. BMI data are analyzed by sex, age group and education level. The distribution of continuous BMI values and their evolution over time are included. In addition, a comparison of measured data with self-reported data is made using survey data. Finally, a brief analysis of the concordance between self-reported and measured data is conducted using data from the 1990 Enquête québécoise sur la santé cardiovasculaire, which provides results for both types of measurements in the same individuals.