OBJECTIVES Current Mexican health care resource-use questionnaires are subjective and not validated through a scientific technique. This generates heterogeneity in costs obtained from several economic evaluations(EE), uneasy to compare methodologically and useless to include in future EE alongside clinical trials. The objective of this study was to develop and validate three instruments to assess resource utilization from the societal perspective. METHODS Three specific instruments were constructed for patients with cardiovascular diseases (hypertension and acute myocardial infarction); oncological (breast, renal and lung cancer) and HIV/AIDS with the aid of a special Mexican consensus. Instruments were subdivided into two sections: recover medical data from hospital records and a survey with patients. The latter was applied to adult Mexican patients from the Social Security Mexican Institute(IMSS) between June and October 2008. Instruments include five dimensions:(diagnostic, treatment and medical follow-up, support services, clinical data and epidemiological data) and pretend to be helpful to obtain direct costs (data collected from hospital records); and indirect and out-of-pocket expenses (data collected from the patient). Sample size estimate used epidemiological Mexican data and statistical tests were performed to demonstrated internal consistency reliability (Cronbach's alpha), interclass correlation coefficient, component analysis (parametric bootstrapping) and construct validity was also evaluated. RESULTS A total of 213 patients were included in the study (31.9% cardiovascular, 30.0% oncological; 38.1% HIV/AIDS). Mean age of participants was 54.9±9.08 years; 49.3% were female. Internal consistency was found in all questionnaires: Cronbach's alpha reported range for cardiovascular patients from 0.73-0.78; cancer patients 0.67-0.80, and HIV/AIDS patients from 0.82-0.87. Higher internal consistency was observed in the out-of-pocket questionnaire(p<0.05). Component analysis showed a few epidemiological variables are responsible for 80% of instrument's variability. CONCLUSIONS Validated resource-use questionnaires are needed to homogenize costs and EE in developing countries. These validated questionnaires in Mexican population could be used by authorities to enhance cost-containment policies.