Incumbent Democratic Treasurer Bill Lockyer was term-limited and ineligible to run for re-election to a third term in office.

Under California's nonpartisan blanket primary law, all candidates appear on the same ballot, regardless of party.

In the primary, voters may vote for any candidate, regardless of their party affiliation.

The top two finishers — regardless of party — advance to the general election in November, even if a candidate manages to receive a majority of the votes cast in the primary election.

Democrat John Chiang and Republican Greg Conlon finished first and second, respectively, and contested the general election, which Chiang won.