Chronic respiratory diseases are an important problem in Chile, causing disability and worsening the quality of life. Aim: To validate the Spanish version of the Chronic Respiratory Questionnaire (CRQ) to be used in Chilean population. Material and methods: The CRQ was applied to 38 patients with chronic respiratory diseases. At the same time the functional and physiologic status of patients (the 6 Minute Walking Test and spirometry) was assessed in an independent and blinded fashion. Results: CRQ scores were associated with 6 Minute Walking Test and forced expiratory volume results (p <0.01 adjusted by age, sex and smoking). The Internal Consistency analysis showed a Cronbach a between 0.60 and 0.89. Conclusions: Considering the construct validation as an on-going process, the present results give additional evidence supporting the use of the CRQ in Chilean population to evaluate the health-related quality of life of patients with chronic respiratory diseases (Rev Méd Chile 2003; 131: 1243-50).