Psicosis debuted in Extreme Championship Wrestling in September 1995, facing Rey Mysterio, Jr. in a bout at Gangstas Paradise.
Psicosis signed with World Championship Wrestling in 1996, anglicizing his name to Psychosis. His debut pitted him against Konnan at Clash of the Champions XXXII. Through the early years, Psychosis would typically face other luchadores, frequently getting a midcard spot during pay-per-view events. He engaged in a feud with Último Dragón, first working as the fan favorite. He was later signed by Dragon's former manager Sonny Onoo, turning into a villain in the process. During the entire length of the feud, he was unable to defeat Dragon. He then began teaming with La Parka under Onoo's tutelage. After Onoo dropped them in favor of Yuji Nagata, the team began to break up, with La Parka attacking Psychosis after the matches. He beat La Parka at Spring Stampede on April 19, 1998. In 1998, Psychosis joined Eddy Guerrero's Latino World Order (LWO) group, which consisted entirely of Mexican wrestlers. The group was disbanded by Ric Flair on the January 11, 1999 episode of Nitro.
During the April 19 episode of Nitro, Psychosis defeated Blitzkrieg, Juventud Guerrera, and Rey Mysterio in a four-way bout to win the WCW World Cruiserweight Championship for the first time. This reign was short-lived however, as he lost it to Rey Mysterio one week later.
Psychosis lost the mask to Billy Kidman on the September 27 episode of Nitro, revealing his face to the American audience. On occasion, he was also paired with Juventud Guerrera. Psychosis had a second Cruiserweight Title reign in WCW shortly after unmasking, when the previous champion Lenny Lane vacated the title. However, on his first televised appearance with the title, Psychosis lost it to Disco Inferno. He was released by WCW in 2000.
After WCW, he made a brief return to Extreme Championship Wrestling that spanned from July to November 2000. The highlight of his second run was a match with Yoshihiro Tajiri at the ECW Arena, as well as an appearance at the Heat Wave pay-per-view, competing in a four-way dance against Yoshihiro Tajiri, Mikey Whipwreck, and Little Guido.
In 2005, Psychosis signed a contract with World Wrestling Entertainment (WWE). He appeared at the WWE promoted ECW One Night Stand pay-per-view on June 12, losing to Rey Mysterio. His first WWE television appearance was on the June 18 airing of WWE Velocity, teaming with Super Crazy to defeat Akio and Billy Kidman. Psicosis, Super Crazy, and Juventud grouped together to form a faction known as The Mexicools. The group made their debut as heels on June 23 when all three members rode to the ring on a John Deere lawn mower, with the sticker saying Juan Deere to be more Mexican, wearing matching coveralls and attacked both Chavo Guerrero and Paul London during their WWE Cruiserweight Championship match. Juventud cut a promo questioning the lack of "true Mexican Luchadores" in the cruiserweight division, before going on to deride the state of Mexican Americans in general. In the following weeks, they would continue to make run-ins in matches and mock the stereotypical image of Mexicans in the United States, even coming to the ring each with their own riding lawn mower.
On July 24 at The Great American Bash in Buffalo, New York, they defeated The Blue World Order in a six-man tag match when Psicosis pinned Steven Richards to secure the Mexicools' first pay-per-view win. The trio then turned face by feuding with Nunzio and Vito. During the December 2 episode of SmackDown!, Super Crazy and Psicosis won a battle royal with five other tag teams, earning a match against MNM at Armageddon for the WWE Tag Team Championship. MNM lost the titles before their match, however, which meant that the Armageddon match was just a standard tag team match. During the January 27, 2006 episode of SmackDown!, Super Crazy and Psicosis defeated The Dicks (Chad and James) and the F.B.I. in a three-way tag team match to win spots in the 2006 Royal Rumble match on January 29. Psicosis entered at number four in the Royal Rumble match but was quickly eliminated by his former WCW rival Rey Mysterio. During June 2006, the ECW brand was revived and with this came the expectations that Super Crazy would leave Psicosis and SmackDown! for the new ECW brand. This was later fueled with a match that would see Yoshihiro Tajiri and Super Crazy team up and face the F.B.I. at One Night Stand. At this time, Psicosis' partnership with Crazy began to crumble when Psicosis abandoned Crazy during incidents with The Great Khali. The team split up, with Psicosis turning heel. On the July 21 episode of SmackDown, Psicosis lost to Super Crazy. This was Psicosis' last WWE appearance. After four months of inactivity, WWE announced that Psicosis was released from WWE in the fall of that year.