A native of Tamaulipas but a resident of Culiacan, Ramirez climbed slowly but steadily on boxing's rankings. In 1978, as a Featherweight, a young Ramirez lost by knockout in two to legendary three time former world champion Ruben Olivares.
After his move in weight to the Lightweights, Ramirez met another boxing legend inside a ring, when he fought Alexis Arguello. Ramirez dropped Arguello in round six, but lost a ten round split decision in Miami. He then faced Ray Mancini for the North American Lightweght belt, and lost a 12 round decision in Ohio. By then, Jose Luis and Julio Cesar Chavez were gymmates and friends.
On May 1 of 1983, Ramirez was given the chance at becoming world Lightweight champion for the first time, when he fought Edwin El Chapo Rosario at the Coliseo Roberto Clemente in San Juan, Puerto Rico, for the World Boxing Council's championship. Ramirez lost a close 12 round unanimous decision, but on November 4, of 1984, he and Rosario had a rematch, also in San Juan. With Rosario pinned against a corner and Ramirez attacking, referee Steve Crosson stopped the bout in round four, after Ramirez had landed 17 straight punches, making Ramirez a world Lightweight champion for the first time, by a technical knockout.
Ramirez then went into training for a defense against Hector Camacho, another boxer from Puerto Rico. The fight was postponed when Camacho suffered a broken ankle during a pick up basketball game, but it finally came off on August 10, 1985. On his first fight telecast on HBO Boxing, Ramirez was dropped in round three and lost a 12 round unanimous decision.
Ramirez, a culturally intellectual person, moved to Paris soon after. There, he re-grouped, and was able to regain the WBC's world championship when Camacho left it vacant, by edging out Terrence Alli with another close but unanimous 12 round decision. He defended the title various times, and then moved back to Mexico. Among the challengers he beat to defend the title was Pernell Whitaker, future multiple time world champion.
Back in Mexico, he and Chavez were neighbors. Chavez had lifted the World Boxing Association's world Lightweight championship by beating Rosario, and a unification bout between the two friends and neighbors was planned. Ramirez, who is a God-father to one of Chavez's sons, lost an 11 round technical decision to Chavez on October 27 of 1988, which marked the last day he would be a world champion.
In 1989, he tried to win the International Boxing Federation's belt from Whitaker, in Virginia, but he lost a 12 round decision. Then, in 1990, he went to Argentina, where he lost to Juan Martin Coggi by a decision in 12 for the WBA's world Jr. Welterweight title. After that bout, he retired.
Ramirez is a member of the less recognized World Boxing Hall of Fame in California, not to be confused with the more widely recognized International Boxing Hall of Fame in Canastota.
His exact record is unknown, as many of his fights were not recorded. It is believed, however, that he fought around 90 times, winning around 80 of them, with about 65 knockout wins.