Few data are available on the association between the present low levels of air pollution in Western Europe and mortality. Daily mortality counts and the concentrations of black smoke, inhalable particles (PM10), sulfur dioxide (SO2), carbon monoxide (CO), and ozone (O3) were available for Amsterdam from 1986 to 1992. We used Poisson regression analysis to control for seasonal and other long-term temporal patterns. Black smoke and PM10 were positively associated with increased risk of mortality. The relative risk for a 100-micrograms per m3 increase in black smoke on the same day was 1.19 [95% confidence interval (CI) = 1.02-1.38], and that for a 100-micrograms per m3 increase in PM10 was 1.06 (95% CI = 0.99-1.14). The relative risk for individuals over 64 years of age was higher. We found no consistent association between the levels of SO2 or CO and daily mortality, but ozone lagged 2 days was positively associated with daily mortality. The effect of particulates on acute mortality was independent of these pollutants. The results of the present study are consistent with the relation reported between particulate air pollution and daily mortality in other communities in Europe and the United States.