The authors have calculated cumulative risks of lung cancer from a case-control study conducted between 1998 and 2002 involving 2,633 lung cancer cases and 2,884 controls in Hungary, Poland, the Czech Republic, Slovakia, Romania, and Russia. The odds ratios for smoking history were combined with national lung cancer mortality rates to obtain the cumulative risk of lung cancer. The cumulative risk of death from lung cancer by the age of 75 years among current male smokers was 14.6% in Romania and Russia and 15.8% in Poland, similar to levels reported in Western Europe, although higher risks were found in the Czech Republic (19.8%), Hungary (21.9%), and Slovakia (28.2%). Cumulative risks of lung cancer death among never smokers of over 1% were observed in Hungary among both men and women and among men in Poland. The effect of quitting smoking on the lifetime cumulative risk was substantial, with between 67% and 83% of lung cancer risk among men being avoided by quitting before the age of 50 years. This substantial reduction in risk among former smokers confirms that lung cancer mortality in Central Europe over the next three decades will be determined by the extent to which current smokers can successfully quit smoking.