Rep. Todd Akin (R-Mo.), who hopes to unseat Sen. Claire McCaskill (D-Mo.) next year, pulled in just over $500,000 in the second quarter.
A campaign aide told Roll Call that Akin raised $512,000 in the quarter and had $1.18 million in the bank at the end of June.
Akin faces former Missouri Treasurer Sarah Steelman in the GOP primary. Steelman, whose campaign has struggled to build momentum, has yet to release fundraising figures for the quarter. The reports covering April through June are due to be postmarked to the Federal Election Commission by midnight Friday.
McCaskill raised almost $1.4 million in the second quarter and had just under $3 million in cash on hand at the end of June.
Roll Call rates the Missouri Senate race a Tossup.