Nearly 4,000 17-year-olds registered in advance of Tuesday's Illinois Primary, Chicago Board of Elections Chairman Langdon Neal said shortly after polls opened.
Several drives were held at area high schools, and Neal said he expects those potential voters to take the additional step of visiting their polling place.
"We expect a lot of our young people to come out today for the first time and exercise their right to vote," he said at a polling place at the American Legion on the 1200 block of West Wrightwood Avenue. "We feel that if they get involved young they'll be voters for life."
In all, Neal said about 9,000 teens registered to vote.
Tuesday's election is the first that some 17-year-olds can vote in Illinois. Gov. Pat Quinn signed the last July that allows them to vote as long as they'll be 18 years of age by the time the General Election rolls around in November.
Tuesday's election narrows the field of candidates for a number of statewide races, including governor and U.S. Senate.