From 1962 to 1976 Spanish cyclist Ventura Díaz competed in 13 editions of the Vuelta a España, with a best finish of ninth in 1974. During this time Díaz also rode in two editions of the Tour de France, as well as the Giro d’Italia in 1976. After some consistent results in his early career he was selected to ride in the individual road race at the 1960 Roma Olympics but did not finish the course. Throughout the 1960s he had multiple podium places at races in Spain, in addition to winning silver in the team time trial at the 1965 UCI World Road Championships, which were held in San Sebastián. Díaz had his best results in 1970 when he won both the Vuelta a los Valles Mineros and the Vuelta a la Comunidad Valenciana stage races. The following year he won the intermediate sprint classification at the Vuelta a España. One of his final wins came in 1975 with a victory on stage 5a at the Tour of the Basque Country.