Data from The Copenhagen City Heart Study, a prospective population study, were analysed to investigate the influence of the type of tobacco and inhalation on pulmonary and total mortality. The study sample comprised 6,511 men and 7,703 women, selected randomly after age-stratification from the general population. There were 2,986 plain cigarette smokers, 3,222 filter cigarette smokers, 1,578 smokers of cheroots/cigars, 433 male pipe smokers and 773 subjects smoking more than one type of tobacco. From 1976 until the end of 1989, 2,765 subjects died. Lung cancer was considered as main death cause in 268. Chronic obstructive pulmonary disease (COPD) was considered as the main cause in 94 cases and main or contributory cause of death in 195 cases (COPD related mortality). Current smokers had a higher risk of total mortality compared to lifetime nonsmokers: the relative risks (RR) ranged between 1.2 for male pipe smokers and 2.4 for female plain cigarette smokers. With regard to lung cancer mortality, the RR ranged between 4.1 for male pipe smokers and 7.9 for female plain cigarette smokers. Even higher RR values were estimated for COPD related mortality. In both sexes, the RR for the investigated end-points were lower in cheroot/cigar smokers and in pipe smokers than in cigarette smokers, but these differences were markedly diminished after an adjustment for the inhalation habit. The present study substantiates the view that tobacco smoking increases pulmonary and total mortality. The small differences between the various types of tobacco are probably caused by different inhalation patterns.