Josh Murphy scored the final penalty kick that earned City a second win on the North American tour.
City won the shoot out 4 - 2 with Joe Day saving two kicks from the Spanish side in the Commonwealth Stadium, Edmonton, Canada. After 90 minutes the game had ended 1 - 1, Omar Bogle headed City into a first half lead from Greg Cunningham's cross before Federico Barba equalised for Valladolid around the hour mark.
The winner was decided by a penalty shoot out with Cardiff scoring four goals through Cunningham, Joe Bennett, Will Vaulks and Murphy. Bogle missed his kick but thanks to Day making those saves Cardiff triumphed.
Junior Hoilett played for an hour in his home country.
Cardiff have one more pre-season game, next Saturday at CCS v French side Nice, ko 3pm.
Cardiff City: Joe Day, Cameron Coxe, Curtis Nelson, Ciaron Brown, Gregg Cunningham, Loic Damour (Will Vaulks 66), Joe Ralls (Aaron Bolger 80), Bobby DeCordova-Reid (James Waite 60), Nathaniel Mendez-Laing, (Josh Murphy 60), Junior Hoilett (Joe Bennett 60), Omar Bogle.