All five members began their music career writing and producing for other artists, establishing them in the world of reggaeton and rap.
In 2007, they joined forces and were taken on by the reggaeton producers of Black Lion Records, Carlos “Karly” Rosario & Elías De León.
Their first studio/compilation album was released on June 26, 2007, and their single hit song No Te Veo MLP reached #1 in The Billboard Hot Latin Charts.
On July 7, 2012, all the members of Los Leones were added on the remix to Yomo's single "En Serio".
On October 6, 2012: Casa De Leones reunited once again for a track made by members J-King & Maximan, "Que La Nota Le Suba" was remixed with the added vocals of Guelo Star, Jowell & Randy.