Her first appearance in media came about when she attended auditions for a Channel 12 TV reality show, Rumbo a la Corona and won a chance to compete for the title of Miss El Salvador in the 2005 competition.

During the final event held on 27 February 2005 before thousands of spectators, she beat the other thirteen contestants and took the crown, thereby earning the right to represent El Salvador in the Miss Universe 2005 pageant.

Dimas also won other additional prizes from sponsors like Avon in categories such as best mouth, best legs, best face, and Miss Internet.

On 31 May 2005, Dimas participated in the Miss Universe contest after months of preparation, but during the final night of the event did not qualify for the fifteen semi-finalists.

On 23 October 2005, Dimas took part in the Miss Earth pageant held in Quezon City, Philippines, where she placed in the top sixteen finalists.