question: Objective. Estimate the prevalence of generalized anxiety disorder (GAD) from April to June 2020. Materials and methods. Repeated cross-sections design based in the Encovid-19, a series of monthly mobile surveys with represen-tative samples of Mexico (N= 833-1 674).The questionnaire includes the GAD-2 scale, and, in July, the GAD-7 scale was added;we examined its internal validity with confirmatory factor analysis and its concurrent validity with sociodemo-graphic variables. Using GAD-7 as criterion, we analyzed the predictive validity of the GAD-2.We estimated the monthly prevalence with the GAD-2. Results. The GAD-7 and the GAD-2 are reliable and valid.The GAD-2 has a sensitivity of 0.87 and a specificity of 0.90.The monthly prevalence remains high and stable, between 30.7 and 32.6%. GAD concentrated in women, unemployed and persons with low socioeconomic status. Conclusions. GAD is a public health problem that worsened during the Covid-19 pandemic. © 2021