Known Aliases: Barrio 18, Calle 18, Mara 18, XVIII, XV3 (coded numeric representation), Eighteens, La 18, Dieciocho, 18th Streeters, Barrio 18 Revolucionarios (Central American faction), Barrio 18 Sureños (Southern California faction)
Origin: Pico-Union / Rampart district, near 18th Street and Union Avenue, Los Angeles, California — circa 1960s. Formed by Mexican-American youth; subsequently distinguished itself by becoming one of the first Hispanic gangs in Los Angeles to recruit members regardless of national origin, accepting Salvadoran, Guatemalan, Honduran, and other Central American immigrants during the 1980s migration wave.
Active Regions: Primary AOR: Los Angeles (Pico-Union, Rampart, Westlake, South LA), San Fernando Valley, Orange County, Inland Empire (CA). Secondary AOR: Nationwide — documented in 120+ U.S. cities across 37 states, with significant clusters in Washington D.C., Houston (TX), Dallas (TX), Atlanta (GA), Charlotte (NC), and New York City (NY). International: Mexico (Mexico City, Chiapas, Tamaulipas), Guatemala (Guatemala City), Honduras (Tegucigalpa, San Pedro Sula), El Salvador (nationwide), Belize. Estimated global membership: 30,000–65,000. Designated as a Transnational Criminal Organization (TCO) by multiple international law enforcement bodies.
Known Alliances: Mexican Mafia (La Eme), Sureños
Known Rivalries: MS-13 (Mara Salvatrucha) — primary rival, representing the most lethal bilateral gang conflict in Central American history, producing thousands of homicides across multiple nations. Florencia 13 — territorial disputes in South LA. All Blood-affiliated sets — opposition within Los Angeles. Norteños — prison and street conflicts. Various rival Sureño cliques — localized territorial friction. Central American military/police units — quasi-insurgency dynamics in Northern Triangle countries.
Primary Identifiers: Colors: Blue and black (Sureños allegiance), khaki. Symbols: Number 18, XVIII, XV3 (15+3=18), Roman numeral XVIII, '666' (6+6+6=18), '99' (9+9=18), devil's horns. Numeric codes: 18, 1-8, 666, 99, 009 (coded). Tattoos: Large 'XVIII' or '18' on torso, back, or face, 'Barrio 18' across chest, gang lifestyle scenes (clown faces, skulls, city skyline), three dots (mi vida loca), regional clique identifiers. Apparel: Los Angeles Dodgers (LA), Duke University (blue), any sports apparel incorporating 18 (number 18 jerseys), dark blue/black Dickies work wear. Hand signs: 1 and 8 finger formations (index finger up, eight fingers subsequently). Graffiti: 'XVIII,' 'B-18,' clique designators, crossed-out '13' (disrespecting MS-13), devil imagery.
Executive Summary:
The 18th Street Gang (Barrio 18) is assessed as one of the largest transnational criminal organizations of street-gang origin, with an estimated global membership between 30,000 and 65,000 operatives dispersed across the United States, Mexico, and Central America's Northern Triangle (El Salvador, Guatemala, Honduras). Originating in the Pico-Union/Rampart area of Los Angeles during the 1960s, the organization distinguished itself through its pioneering multi-ethnic recruitment policy — a strategic departure from the traditionally monoethnic Hispanic gang model — which enabled explosive growth during the 1980s Central American immigration influx. The 18th Street Gang operates under the broader Sureños umbrella, maintaining tributary allegiance to the Mexican Mafia (La Eme) within the California prison system, though Central American factions (Revolucionarios and Sureños splits) have demonstrated increasing operational autonomy.
Principal criminal enterprises encompass industrial-scale narcotics trafficking (methamphetamine, cocaine, heroin, fentanyl, cannabis), human smuggling/trafficking, extortion of local businesses and public transportation systems (particularly in Central America), arms trafficking, kidnapping for ransom, contract murder, money laundering, and immigration document fraud. The 18th Street–MS-13 rivalry constitutes one of the most violent bilateral gang conflicts globally, generating thousands of homicides across multiple continents. U.S. federal prosecutions — including multiple RICO cases in the Central District of California and large-scale ICE/HSI deportation-focused operations — have targeted leadership nodes, yet the organization's decentralized clique-based structure and transnational operational depth continue to challenge suppression efforts. The U.S. Department of Treasury's OFAC has sanctioned 18th Street leadership under Executive Order 13581 targeting transnational criminal organizations.