There is little information about the trend of the gender gap in chronic morbidities and whether the trend of expansion occurs equally in the age and gender groups. The objectives were to examine the consistency and stability of the gender gap in the main self-reported chronic morbidities in the general population, and, likewise, to analyze the trend of major chronic morbidities between 1997 and 2015 in men and women across age groups. The data were extracted from the Canary Health Survey, which uses a probabilistic sampling in the population >16 years of age, for the years 1997 (n = 2167), 2004 (n = 4304), 2009 (n = 4542), and 2015 (n = 4560). The data for the twelve most frequent chronic morbidities were analyzed using logistic regression, estimating the annual change ratio between 1997 and 2015, adjusting for age and educational level. The interaction of age with the period (1997–2015) was examined to analyze the rate of change for each morbidity in the age groups. Musculoskeletal diseases, headaches, anxiety and depression, and peripheral vascular diseases showed a stable gender gap across observed years. High cholesterol and high blood pressure tended to a gap reduction, while heart disease, diabetes, and respiratory disease did not show a significant gender gap along the period. The trend of the main chronic morbidities increased similarly in men and women in all age groups, but significantly in women older than 60 years and in men older than 45 years. Aging explained a substantial part of the trend of increasing prevalence of the main chronic morbidities, but not totally. Factors other than age and education are driving the increase in chronic morbidity in older age groups.