The goal of this study was to verify the prevalence of patients with mental disorders treated in hospitals and health centres of Itajubá (MG). An observational, descriptive, cross-sectional and retrospective study was carried out, analysing medical records through descriptive statistics. It was estimated prevalence of 25% and less expected of 22%, confidence level was 95% and power of 80%, with a sample of 1298 people. The BioEstat 5.0 program was used for chi-squared statistical tests with bivariate data analysis. In the result, the association between the prevalence of mental disorders was 27.6% for depression and 46.6% for anxiety. There was a prominence of depression among women aged 40 to 49 years and over 60 years and an important evidence of anxiety in women aged 40 to 49 years and 20 to 29 years; Almost 1.5 times higher in the development of anxiety in detriment of depression. Therefore, the data corroborate the multifactorial nature of mental health problems, aiming the improvements of actions related to the patients’ quality of life, identifying the factors associated with the mental disorders, and raising the awareness of the health team and the population about the importance of this theme.