In the 4x100 metre medley relay, Belmonte swam the breaststroke leg of the relay in a time of 1:10.46 with Nina Zhivanevskaya swimming the backstroke leg, Ángela San Juan swimming the butterfly leg, and María Fuster swimming the freestyle leg. The relay finished 15th in the prelims heats with a time of 4:06.40 and did not advance to the final.