| Registered voters | 87,102 | Official Canvassed Results |
| Total voters | 8,985 | |
| Turnout | 10.32% | |
| Early voters | 2,150 | |
| % of votes cast early | 23.93% | |
| DEMOCRATIC PRIMARY | ||
| Total Voters | 4,138 | 6/23/10 9:52 AM |
| US Senate | ||
| Roxanne Conlin | 3,166 | 80% |
| Thomas L. Fiegen | 412 | 10% |
| Bob Krause | 355 | 9% |
| Write-Ins | 9 | 0% |
| US Rep (2nd Dist) | ||
| Dave Loebsack | 3,735 | 99% |
| Write-Ins | 34 | 1% |
| Governor | ||
| Chet Culver | 3,568 | 98% |
| Write-Ins | 88 | 2% |
| Secretary of State | ||
| Michael A. Mauro | 3,312 | 99% |
| Write-Ins | 17 | 1% |
| Auditor of State (Jon Murphy later nominated at convention) | ||
| Write-Ins | 175 | 100% |
| Treasurer of State | ||
| Michael L. Fitzgerald | 3,370 | 100% |
| Write-Ins | 9 | 0% |
| Secretary of Agriculture | ||
| Francis Thicke | 3,150 | 100% |
| Write-Ins | 15 | 0% |
| Attorney General | ||
| Tom Miller | 3,498 | 99% |
| Write-Ins | 22 | 1% |
| State Senate (15th Dist) | 25 | of 25 precincts |
| Robert E. Dvorsky | 1,516 | 99% |
| Write-Ins | 10 | 1% |
| State Senate (39th Dist) | 25 | of 25 precincts |
| Joe Bolkcom | 1,887 | 99% |
| Write-Ins | 15 | 1% |
| State Senate (45th Dist) | 8 | of 8 precincts |
| Becky Schmitz | 106 | 99% |
| Write-Ins | 1 | 1% |
| State Rep (29th Dist) | 15 | of 15 precincts |
| Nathan Willems | 311 | 100% |
| Write-Ins | 0 | 0% |
| State Rep (30th Dist) | 13 | of 13 precincts |
| Dave Jacoby | 1,165 | 88% |
| John J. Stellmach | 159 | 12% |
| Write-Ins | 3 | 0% |
| State Rep (77th Dist) | 13 | of 13 precincts |
| Mary Mascher | 647 | 99% |
| Write-Ins | 9 | 1% |
| State Rep (78th Dist) | 13 | of 13 precincts |
| Vicki Lensing | 1,223 | 99% |
| Write-Ins | 8 | 1% |
| State Rep (79th Dist) | 5 | of 5 precincts |
| Write-Ins | 4 | 100% |
| State Rep (89th Dist) | 8 | of 8 precincts |
| Larry K. Marek | 107 | 100% |
| Write-Ins | 0 | 0% |
| Board of Supervisors (2 to be nominated) | ||
| Janelle Rettig | 3,124 | 75% |
| Sally Stutsman | 2,927 | 71% |
| Write-Ins | 70 | 2% |
| County Treasurer | ||
| Thomas L. Kriz | 3,385 | 100% |
| Write-Ins | 17 | 0% |
| County Recorder | ||
| Kim Painter | 3,389 | 100% |
| Write-Ins | 14 | 0% |
| County Attorney | ||
| Janet M. Lyness | 3,450 | 99% |
| Write-Ins | 38 | 1% |
| REPUBLICAN PRIMARY | ||
| Total Voters | 4,847 | |
| US Senate | ||
| Chuck Grassley | 4,170 | 98% |
| Write-Ins | 87 | 2% |
| US Rep (2nd Dist) | ||
| Mariannette Miller-Meeks | 2,646 | 58% |
| Steven R. Rathje | 969 | 21% |
| Rob Gettemy | 572 | 13% |
| Christopher Reed | 377 | 8% |
| Write-Ins | 6 | 0% |
| Governor | ||
| Terry E. Branstad | 2,944 | 61% |
| Bob Vander Plaats | 1,641 | 34% |
| Rod Roberts | 229 | 5% |
| Write-Ins | 3 | 0% |
| Secretary of State | ||
| Matt Schultz | 1,464 | 45% |
| Chris Sanger | 889 | 28% |
| George S. Eichhorn | 856 | 27% |
| Write-Ins | 16 | 0% |
| Auditor of State | ||
| David A. Vaudt | 3,253 | 99% |
| Write-Ins | 20 | 1% |
| Treasurer of State | ||
| David D. Jamison | 1,974 | 65% |
| James A. Heavens | 1,037 | 34% |
| Write-Ins | 16 | 1% |
| Secretary of Agriculture | ||
| Bill Northey | 3,329 | 100% |
| Write-Ins | 16 | 0% |
| Attorney General | ||
| Brenna Findley | 3,071 | 99% |
| Write-Ins | 22 | 1% |
| State Senate (15th Dist) | 25 | of 25 precincts |
| Write-Ins | 57 | 100% |
| State Senate (39th Dist) | 25 | of 25 precincts |
| Write-Ins | 52 | 100% |
| State Senate (45th Dist) | 8 | of 8 precincts |
| Sandra Greiner | 251 | 69% |
| Randy J. Besick | 57 | 16% |
| Rick Marlar | 53 | 15% |
| Write-Ins | 1 | 0% |
| State Rep. (29th Dist.) | 15 | of 15 precincts |
| Shawn Graham | 563 | 100% |
| Write-Ins | 2 | 0% |
| State Rep (30th Dist) | 13 | of 13 precincts |
| Write-Ins | 34 | 100% |
| State Rep (77th Dist) | 13 | of 13 precincts |
| Write-Ins | 16 | 100% |
| State Rep (78th Dist) | 13 | of 13 precincts |
| Write-Ins | 25 | 100% |
| State Rep (79th Dist) | 5 | of 5 precincts |
| Jeff Kaufmann | 107 | 98% |
| Write-Ins | 2 | 2% |
| State Rep (89th Dist) | 8 | of 8 precincts |
| Jarad Klein | 275 | 80% |
| Chris Canny | 68 | 20% |
| Write-Ins | 0 | 0% |
| Board of Supervisors (2 to be nominated) | ||
| Write-Ins | 180 | 100% |
| County Treasurer | ||
| Write-Ins | 56 | 100% |
| County Recorder | ||
| Write-Ins | 51 | 100% |
| County Attorney | ||
| Write-Ins | 65 | 100% |