Introduction:-Anxiety disorders have a prevalence of 14%; Psychiatric comorbidities are more common in patients with chronic respiratory diseases such as asthma and chronic obstructive pulmonary disease. Rates of 12 to 34% prevalence of anxiety and depression disorders have been found among adult patients with asthma. Objective:-to identify the prevalence of anxiety in adult patients with asthma. Material and Methods: observational, transversal and analytical study. Demographic data collection was performed, stratified by level of asthma control, according to international criteria, spirometry and application of the Beck anxiety inventory, validated in Mexico. A sample size calculation (204 patients), bivariate and multivariate analysis with multiple logistic regression was performed. Results: We included 204 patients, 59.8% men; 50% with controlled asthma, 34.7% partially controlled asthma and 16. 7% uncontrolled asthma. The prevalence of anxiety was 77.5%, 18.5% with minimal anxiety, 44.3% mild, 28.8% moderate and 8.5% severe. Forty percent of patients with partially controlled asthma with moderate anxiety and 68.7% with uncontrolled asthma had moderate anxiety. The associated factors that predispose to anxiety were: uncontrolled asthma, obstructive pattern in spirometry, female sex, more than 5 years of onset of bronchial symptoms and the presence of comorbidities. Conclusions: in this study we found a higher prevalence of anxiety in patients with asthma, than that reported in the literature.