"El Perdedor" (English: The Loser) is Aventura's third single from album K.O.B. Live (2006). The song reached big recognition in many Spanish-speaking countries. and reached the top five of the Billboard Hot Latin Tracks. A remix was made for the song featuring Ken-Y.

The music video for "El Perdedor" is about a man who is too focused on his work and career and thus ignores pretty much ignores his lover. She is trying to make some time for them but he always puts work on top of her. Eventually, after many times of being disappointed, another man gains her attention as he is interested in her and shows it by devoting time to her.

The song was awarded Tropical Airplay Song Of The Year by a Duo Or Group and Latin Rhythm Airplay Song Of The Year by a Duo Or Group in the 2009 Latin Billboard Music Awards. It was also awarded the Lo Nuestro Award for Tropical Song of the Year in 2009.