Duration of smoking career, number of cigarettes smoked and smoke inhalation pattern seem to have a bearing on the occurrence of tobacco-related lung diseases. The authors therefore determined the smoking pattern and especially the time relation between drawing on a cigarette and inhalation in smokers with and without tobacco-related lung diseases. Based on clinical and radiological findings as well as pulmonary function tests, 91 smokers (without lung disease, with small airway disease, with simple chronic bronchitis, with obstructive bronchitis, with bronchitis and predominantly emphysema and with lung cancer) were examined. Smoking and breathing pattern were recorded using a smoke flow machine and a strain-gauge belt while smoking a cigarette. The blood level of COHb was determined before and after smoking. Of the smoking characteristics peak pressure, peak flow, time from drawing to inhalation and COHb difference varied significantly among the different groups. Drawing-to-inhalation time was lowest in smokers with chronic bronchitis and predominantly emphysema, which differed significantly from the other groups. This characteristic may be the consequence or the cause of emphysema. Regarding the latter, smokers with emphysema may perhaps lack the acute airway response to smoke inhalation and thus be able to inhale the cigarette smoke directly.