Objective To examine the relationship between smoking and tobacco-related mortality in a cohort of the aged Chinese armymen.Methods A cohort study was carried out in Xi'an,China from 1987 to 2005.A total of 1 268 retired male military cadres aged 55 or older were examined in 1987 and followed up in the next 18 years.At baseline,388 men were non-smokers,461 were former smokers,and 419 were current smokers.The current smoking rate was 33.04%,Quitted rate was 52.39%.The terminal main observation items included all-cause and tobacco-associated mortality.Results Up to Jun 30,2005,a total of 491 subjects died.Compared with non-smokers,the relative risks(95% confidence intervals(CI)) of ever-smokers for all-cause deaths,chronic obstructive pulmonary disease(COPD),lung cancer,and coronary heart disease(CHD) were 1.24(1.01-1.53),1.91(1.06-3.46),2.91(1.36-6.23),and 1.15(0.68-1.93),respectively.Compared with current smokers,the risks of total mortality and death from lung cancer for former smokers were decreased by 66.7% and 14.98%,respectively.Conclusions Cigarette smoking was a major death risk factor in the cohort and quitting smoking could save lives.