OBJECTIVES: A survey was conducted to compare smoking behavior and self-reported respiratory symptoms of persons with and without diagnosed COPD. METHODS: In a study conducted within the Saskatchewan Health database, persons over 40 years old with diagnosed COPD, emphysema or chronic bronchitis and at least two bronchodilator prescriptions within six months of respiratory diagnosis were identified (N = 11,493). An age/gender matched comparison group without COPD, asthma or any respiratory diagnoses or medications was identified (N = 22,986). A survey was mailed to an age/gender stratified random sample of 4002 subjects, half from the COPD group and half from the comparison group. RESULTS: The response rate was 41% among COPD patients and 40% in the comparison group. Among those with COPD, 80% had ever smoked, compared with 53% of those without COPD (OR: 4.01, CI: 3.19-5.04). Among ever smokers, 16% of COPD and 11% of non-COPD subjects were current smokers (OR: 1.58, CI: 1.09-2.29). A large proportion of the smokers, 73% in the COPD group and 49% in the non-COPD group, had smoked for over 30 years. Odds ratios for self-reported symptoms of COPD comparing the COPD cohort to non-COPD were 11.0 (CI: 8.1-15.1) for persistent cough, 10.4 (CI: 8.1- 13.6) for phlegm with cough, 25.1 (CI: 18.5-34.0) for wheezing, and 18.5 (CI: 13.8-24.8) for shortness of breath with mild exercise. Among the subjects classified as non-COPD, 20% reported having any of the above-mentioned respiratory symptoms and only 2% reported having all four symptoms. CONCLUSIONS: Persons with diagnosed COPD are more likely to have been smokers in the past and had a longer smoking history than persons without COPD. Crude measures such as the proportion that ever smoked may not capture substantial differences in smoking-related illness. Self-reported respiratory symptoms supported the categorization of COPD vs. non-COPD made using administrative data.