Incumbent Republican Senator Chuck Grassley defeated Democratic nominee Michael Franken to win re-election to an eighth term.

Despite his victory, this was Grassley's closest Senate race since he was first elected in 1980 and worst performance as he did not crack 60% of the vote.

Former U.S. Representative Abby Finkenauer was the original frontrunner in the Democratic primary, with her campaign being backed by several prominent politicians and labor unions, as well as the influential political action committee EMILY's List.

[25] However, in an upset, retired vice-admiral Michael Franken managed to slowly overtake her as the perceived frontrunner, assisted by an effective campaign that highlighted his leadership credentials.

Representatives State officials State legislators Local officials Labor unions Newspaper and other media Organizations Individuals Aggregate polls Graphical summary Chuck Grassley vs. Abby Finkenauer Grassley won all 4 congressional districts.