The Workers' Socialist Organization (Spanish: Organización Socialista de los Trabajadores, OST) was a small Trotskyist political party in Bolivia.
The Workers' Socialist Organization was established by a dissident fraction which broke away from the Communist Vanguard of the Revolutionary Workers' Party in 1978.[1] It was led by Sonia Montafto.[2]
In 1979 the OST allied with the Socialist Party-One and its candidate Marcelo Quiroga Santa Cruz.[3]
In 1980 the OST allied with the Revolutionary Party of the Nationalist Left and its candidate Juan Lechín Oquendo.[4]