To adapt the 7-item Generalized Anxiety Questionnaire (GAD-7) from English to the cultural and linguistic context of Quechua Collao and to analyze its psychometric properties in Puno, Peru. The GAD-7 in its original version was translated into the Collao Quechua variety and its psychometric properties were analyzed. The participants were bilingual (Spanish and Quechua), over 18 years of age and of both sexes. The exploratory factor analysis (EFA) was evaluated using parallel analysis, confirmatory factor analysis (CFA) and goodness-of-fit indices; reliability was also analyzed using McDonald's classic alpha and Omega. Judges and focus group participants conducted the cultural and linguistic adaptation of the GAD-7 to Quechua Collao; the EFA reported the presence of a single factor (KMO=0.88, p=0.01); while the CFA confirmed adequate adjustments in the unifactorial model (CFI=0.994; TLI=0.991; SRMR=0.027; RMSEA=0.092), good reliability (α=0.896; ω=0.894) and was also invariant across age groups, sex, marital status and educational level. The questionnaire showed validity for a unidimensional model of the GAD-7 adapted to the Collao Quechua, as well as optimal reliability and invariance by the evaluated groups. Its use could benefit anxiety research and care.