We analyse voter turnout using data from 309 local Norwegian language referendums carried out during 1965–2005, emphasising the effect of referendum type and changes in suffrage. The largest determinant of voter participation is suffrage: The contraction of voting rights to parents with children in school leads to an 18 percentage point average increase in turnout, even after controlling for electoral size effects. The data fail to corroborate our prediction that turnout is significantly higher in semi-binding than advisory referendums. The evidence confirms our hypotheses that turnout is negatively correlated with electoral size and positively correlated with electoral competition.