Abstract Background The measurement of the experience perceived and reported by patients and families is essential to improve the care process. In the literature, a wide variety of questionnaires and supra-specialized scales are provided for services, pathologies or areas of care, making it difficult to compare their results. Our objective was to design and psychometrically validate a questionnaire to measure the experience of patients treated in hospitals and outpatient services and possibly virtual services. Method This was a survey and validation study of instruments with adult patients treated in eight clinics and 28 medical centers. The QEx-P Questionnaire was designed and administered electronically. Construct validity was evaluated with AFE and CFA; convergent and discriminant validity with Spearman's coefficient and Fornell's criterion, respectively; and reliability with Cronbach's alpha. Results A total of 2972 surveys were analyzed. In the validation of the construct, 12 models were estimated, finding a better goodness of fit in the 5-factor models for outpatient and hospital care and 1-factor for virtual care. The convergent validity showed a moderate correlation with the NPS. The discriminant validity was indeterminate. Reliability showed high internal consistency. Conclusion The questionnaire designed and validated in this study has psychometric validity and reliability as a tool to measure the experience reported by Spanish-speaking patients attended in outpatient and hospital services, in addition to being potentially useful for measurement in virtual services (calls or telehealth).