He was also known as Eddie, and was sometimes introduced as Eddie Vallejo. As an adult, and in order to find more professional bouts, he moved to Tyler, Texas. Vallejo started his professional boxing career on June 15, 1990, losing to Pauline Pumarejo by a four round points decision in Matamoros, Tamaulipas.
His next fight was his first fight abroad as a professional, when he traveled to London, England, to box Mickey Cantwell on January 21, 1991, losing that bout by knockout in round 4.
Vallejo"s first victory as a professional came during his third fight, when he defeated Amado Morado, on September 10, 1991, by a four round decision at McAllen, Texas, United States. He then lost to Aureo Dominguez and Hector Lara, both by 4 round decision, and both in Texas.
Robles was 0-2 coming into their fight. Despite having a record, until then, of 2 wins and 5 losses, Vallejo"s next bout was an eliminator for a world championship fight.
Next, Vallejo traveled to San Juan, Puerto Rico, where he opposed Josué Camacho for the WBO"s vacant world Junior-Flyweight crown, at the Caribe Hilton Hotel.
Vallejo continued fighting after the Camacho loss for two more years, but he lost all his fights thereafter.