The authors estimated the number of premature deaths from particulate matter less than 2.5 microm (PM2.5) that would result from making 29 proposed fossil fuel power plants in Virginia operational. We used a U.S. Environmental Protection Agency air quality model (Climatological Regional Dispersion model) to calculate changes in ambient concentrations of PM2.5 and Cox proportional hazard modeling to calculate the resulting premature mortality. The model predicted that if all 29 plants were operational, PM2.5 concentrations would rise in 271 counties across 19 states 5 and increased average annual PM2.5 concentrations would result in a rate of 17 deaths per 37,900,026 people aged 30 yr and older (0.45 deaths per million, 95% confidence interval = 0.31, 0.59) per year by the end of 2004, increasing thereafter. Over a 6 yr period, 104 cumulative excess deaths would occur due to operations of these proposed plants. The authors recommend that precautionary principles be considered when policy decisions related to energy production from fossil fuels are made.