Partido Socialista de los Trabajadores (PST) was a Trotskyist Spanish political party founded in 1979 and dissolved in 1993.

On February 1, 1980 Yolanda González Martín, a prominent student leader and member of the PST, was kidnapped and murdered in Madrid by members of a right-wing terrorist group.

[2] Her murderer today works for the Ministry of the Interior.

[3][4] In 1993 it was divided into two sectors: PST (Verdad Socialista), which in 1994 merged with the Group for the construction of a Revolutionary Workers Party (GPOR) to create the Workers' Revolutionary Party (PRT), that in 1998 joined United Left; and PST (Contra Corriente) that was dissolved a few months later.

This article about a political party in Spain is a stub.