After a four month spell as a stagiaire (trainee), Jiménez turned professional at the beginning of the 1993 season with the Spanish team Banesto which he would be a part of for the rest of his career.
[2] In his first year, his teammates included Tour de France champions Pedro Delgado and Miguel Induráin.
[5] His four triumphs in the mountains classification of the Vuelta places him behind only José Luis Laguía as the rider with the most wins in the competition in the history of the race.
[5] Of other noteworthy results, Jiménez won the Spanish National Road Race Championships in 1997 and secured overall victories in the 2000 Volta a Catalunya and in the Vuelta a La Rioja in both 1994 and 1997.
After a modest Giro d'Italia debut with 26th place in 1995,[16] he was appointed leader of his Banesto team for the 1999 race and started off well by finishing 2nd after Marco Pantani on stage 8.
[18] He had more luck in his Tour de France starts, finishing 8th overall in 1997 after a consistent performance which included four top 10 results on individual stages.
Jiménez attacked the 23% gradient of the Angliru in rain and fog to catch Pavel Tonkov's long solo break at the line and take the stage in a two-man sprint.
Jiménez received psychological treatment for depression, and retired from professional cycling in 2002, at which point he got married.