Halfway through the 2004 Vuelta, it appeared it would become an easy win for Heras, but in the last week his fellow countryman Santiago Pérez won two heavy mountain stages, thus becoming an important rival. Eventually Heras won with only 30 seconds advantage on Pérez. Francisco Mancebo, also from Spain took third. The first non-Spaniard was Stefano Garzelli from Italy in 11th. The points jersey was won by Erik Zabel from Germany, the mountain jersey was won by Félix Cárdenas from Colombia and the combination jersey was won by Roberto Heras. Kelme was the winner of the team ranking. Alessandro Petacchi, an Italian sprinter won four stages, but he didn't finish the Vuelta. Pérez Fernández won three stages.
Phonak hearing systems teammates Tyler Hamilton and Santiago Pérez would later test positive for blood doping from blood samples taken during the race.