The research examines both aggregate and individual level data in the state of Oregon—the only state that conducts all of its elections by mail. The aggregate analysis of 46 statewide elections (1980–2008) suggests that the vote-by-mail format is a major stimulus to voter participation in special and presidential elections in Oregon, while its effect on turnout in primary and off-year general elections is insignificant. Additional analysis of the official centralized voter registration lists in Oregon from 2000 to 2007 (approximately 2 million registered voters) confirms this tendency of Oregon voters to abstain in special elections, particularly for younger voters. These findings also suggest that voter turnout since the adoption of vote-by-mail in 1998 has been slightly lower for Republicans than for Democrats in primary elections and special elections.