Mijares comes from a large boxing family. His younger brother is a Lightweight prospect Ricardo Mijares and his uncle is a former world title contender Vicente Mijares.
Professional career
On June 3, 2006, Mijares knocked out Adalberto Davila in six rounds for the Mexican Super Flyweight title.
WBC Super Flyweight Championship
On September 18, 2006, he defeated former champion Katsushige Kawashima for the Interim WBC title, by a split decision. The Official scorers saw it 114-113, 113-114, 114-113. He was later promoted to full champion after reigning champion Masamori Tokuyama vacated his title on December 6, 2006, in anticipation of retiring. In 2007, he defeated Katsushige Kawashima in a rematch via a tenth round knock out. On April 14, 2007, Mijares defended his title by beating two time Light Flyweight Champion Jorge Arce by unanimous decision in a particularly bloody match for Arce, who saw his first defeat since 1999. Mijares won the fight by a wide margin, with the official judges scoring the match 119-109, 118-110, 117-111, all in favor of Mijares. Mijares returned just 3 months later, beating Teppei Kikui, dominating and then stopping him in 10 rounds in front of his hometown crown in Mexico. Mijares made quick work of obscure journeyman Franck Gorjux stopping him in just 1 round.
In February 2008, Mijares returned to the United States and was featured on a HBO pay-per-view under card against Flyweight Olympian Jose Navarro, the early rounds belonged to Mijares, while the middle rounds were evenly matched with Mijares finishing strong in the later rounds. Mijares retained his title with a Split Decision victory.
WBA Super Flyweight Championship
Mijares unified his WBC Super Flyweight title by defeating WBA Champion Alexander Muñoz via split decision on May 17, 2008. After several close opening rounds, Mijares took control with his crisp counterpunching and brilliant defense, with the win being secured by many dominant late rounds in which he managed to hurt Munoz. This win made him the WBA Champion. With the victory, Mijares earned a spot in the top 10 pound for pound list. Mijares made a return on August 30 in Mexico, where he defended his two crowns against a 38-year-old former WBC Flyweight Champion, Chatchai Sasakul. Sasakul had lost his title to Manny Pacquiao in 1998 and had not fought any world class opposition since. Mijares easily controlled the contest with his jab and counterpunching, eventually stopping Sasakul in round 3 after dropping him in the previous round. Mijares was most recently knocked out by Vic Darchinyan in the 9th round, losing his WBC and WBA Super Flyweight titles to the Armenian-born Australian in a surprising upset. Although he had three defeats prior to his bout with Darchinyan, this was the first time Mijares had been stopped. He went up in weight and challenged Nehomar Cermeño for the Interim WBA Bantamweight title on March 14, 2009. Mijares lost by split decision. He fought Cermeño again on September 12, 2009 for that same title but lost by unanimous decision. Two days later, Mijares announced his retirement from boxing.
On June 16, 2018, Mijares headlined his retirement card before a partisan crowd at Gómez Palacio, losing by third round knockout to Wilfredo Vázquez Jr. of Puerto Rico.
