OBJECTIVES: To investigate the relationship of severity levels of anxiety identified by the GAD-7 scale and the degree of disability as assessed by other standard widely used questionnaires. METHODS: A random sample of 212 subjects was recruited in Mental Health and Primary Care centres; 50% diagnosed of Generalized Anxiety Disorder (GAD) by DSM-IV criteria, and the other 50% were concurrent matched controls. In addition to the GAD-7, the following scales were also administered: Hamilton Anxiety scale (HAM-A), Hospital Anxiety and Depression Scale (HADS), and World Health Organization Disability Scale (WHO-DAS). The number of visits to primary care and specialized services were also measured. Correlations between scale scores were computed and also agreement between instrument-specific disability and severity levels. RESULTS: Strong and significant (p<0.001) correlations were found between GAD-7 scores and other questionnaires: HAM-A (r=0.852), HADS-A (r=0.903), WHO-DAS (r=0.704). Although GAD-7 scores correlated with all WHO-DAS dimensions, higher correlations were observed with Social Participation (r=0.741), Comprehension and Communication (r=0.679), and Labour (0.638) dimensions. Moderate but significant correlations were also found between GAD-7 scores and the number of visits to Primary Care (r=0.393) and Specialized Services (r=0.373). HAM-A severity groups presented significant differences in GAD-7 mean scores (F=205.3; df1=3; df2=208; p<0.001), and HAM severity groups also differed (F=175.3; df1=3; df2=208; p<0.001); in both cases all severity levels differed. CONCLUSIONS: The GAD-7 scale has shown to highly correlate not only with specific anxiety measures but also with disability measures. Not all WHO-DAS disability dimensions seem to be equally affected by GAD levels, and it has been shown that more severe GAD levels tend to demand more health attention. As the GAD-7 is self-administered and it is no time consuming, this instrument could be a good choice in primary care settings to explore the level of patient’s disability in subjects with GAD.