The authors examined the effect of a large reduction in the price of alcohol in Finland in 2004 on alcohol-related mortality by age and socioeconomic group. For this register-based study of Finns aged >or=15 years, data on independent variables were extracted from the employment statistics of Statistics Finland. Mortality follow-up was carried out for 2001-2003 (before the price reduction) and 2004-2005 (after). Alcohol-related causes were defined using both underlying and contributory causes of death. Alcohol-related mortality increased by 16% among men and by 31% among women; 82% of the increase was due to chronic causes, particularly liver diseases. The increase in absolute terms was largest among men aged 55-59 years and women aged 50-54 years. Among persons aged 30-59 years, it was biggest among the unemployed or early-age pensioners and those with low education, social class, or income. The relative differences in change between the education and social class subgroups were small. The employed and persons aged <35 years did not suffer from increased alcohol-related mortality during the 2 years after the change. These results imply that a large reduction in the price of alcohol led to substantial increases in alcohol-related mortality, particularly among the less privileged, and in chronic diseases associated with heavy drinking.