With the Kentucky Derby just over a month away, the final chance to nominate horses to the 2006 Triple Crown closed on March 25. Early nominations, which only cost $600, closed in January while the late nominations were $6000 each. Same as last year, 14 more colts were added to the list with Cause to Believe, winner of the California Derby, and With a City, winner of the Lane's End Stakes, topping the list of new faces.
If any additional horses not already nominated want to enter, they will have to be supplemented. Cost for this is $150,000 for the Kentucky Derby and $100,000 for the Preakness and Belmont. Even if a horse is supplemented, he is the lowest in priority for getting in the race with any early or late nominee getting preference over him. For the early and late nominees, graded stakes earnings determine their priority with the field limited to 20 starters for the Kentucky Derby with no also-eligibles allowed.
| Horse | Sire | Trainer | Owner |
| Cause to Believe | Maria's Mon | Jerry Hollendorfer | Peter Abruzzo & Peter Redekop |
| Devilofarush | Wild Rush | Michael Maker | Equirace.com |
| Double Galore | Grand Slam | Myung Kwan Cho | |
| High Blues | High Yield | David Paulus | Dixiana Stables |
| Kellers Church Rd. | Pioneering | Meares | Briter Stable |
| Malameeze | Saint Ballado | Bobby Barnett | Mark Stanley |
| Mister Triester | Old Trieste | Warren Stute | B.W. Hughes |
| Nob Hill Deelite | Afternoon Deelites | Patrick Mouton | Bienstock & Winner Stable |
| Oh So Awesome | Awesome Again | Jean Claude Rouget | Team Valor |
| Sam's Ace | In Excess | Doug O'Neill | J. Paul Reddam & Aron Wellman |
| Sayhellotolarry | Victory Gallop | Harold Williams | Frances Genter Williams |
| Showing Up | Strategic Mission | Barclay Tagg | Lael Stable |
| With a City | City Zip | Michael Maker | Equirace.com |
| Where's That Tiger | Storm Cat | De Kock | L.M. Nestadt & B. Kantor |
