<sec><title>BACKGROUND</title>Spirometry is the keystone to diagnosing chronic obstructive respiratory diseases (CORD), but it is unavailable in Vietnam. The study aims to develop a questionnaire to screen patients requiring spirometry.</sec><sec><title>METHODS</title>This cross-sectional study included consecutive volunteers visiting District 10 and District 12 hospitals in Vietnam. Based on chronic clinical symptoms (history of TB, chronic bronchitis, asthma and occupation risks, cumulative smoking and exposures to indoor pollution factors), a questionnaire was developed and submitted to each subject. Spirometry was also obtained. CORD was defined by airways obstruction with FEV1/FVC < LLN. A multivariate model was applied to determine the statistically significant variables as possible CORD predictors.</sec><sec><title>RESULTS</title>1,877 subjects were recruited, and 16% were diagnosed with CORD. Among 267 subjects with a history of asthma, 153 had airways obstruction (OR = 14; 95%CI 10-18). Among the 1,610 subjects with no history of asthma, there were 9% of CORD; based on ROC curve analysis, the best predictors of CORD were cumulative smoking, history of TB, current breathlessness and wheezing, with 57% of sensitivity and 82% of specificity.</sec><sec><title>CONCLUSION</title>among the non-asthmatic population, a questionnaire based on four items can identify subjects requiring spirometry to diagnose airways obstructive diseases.</sec>.