The validity of a French version of a disease specific quality of life instrument, the St George's Respiratory Questionnaire, has been assessed in a sample of 64 patients with chronic respiratory disease undergoing oxygen therapy. The studied properties were internal consistency, test-retest reproducibility and criterion validity. The St George's showed a good internal consistency with Cronbach's alpha coefficients from 0.61 to 0.95 and a good reproducibility with Intraclass Correlation Coefficients (ICC) from 0.67 to 0.95. High correlation with dyspnea (p=0.0004 to 0.01) showed a correct criterion validity. So psychometric properties of the French version of the questionnaire are good. However, its administration caused a few problems, and we advice it to be administered by a trained interviewer in such patients.