It joined the Communist International on its second attempt, at whose sixth congress Ricardo Paredes was the only Ecuadorian representative after the more socialist/left-liberal oriented general secretary Carrera Andrade was not granted a visa for the Soviet Union in time.

Paredes subsequently replaced Carrera Andrade as general secretary and pursued a course of orientation of the PSE as a communist party, which was renamed Partido Socialista Ecuatoriano, sección de la III Internacional Comunista in 1929.

In 1931 there was a rift between revolutionary communists loyal to Moscow and more reform-oriented "socialists" in the party, which was subsequently renamed "Partido Comunista del Ecuador" under the leadership of Paredes.

[8] In 1946, after the failure of the alliance with conservative José María Velasco Ibarra, the party lost its legal registration and was forced underground, with the consequent imprisonment of numerous members.

[9] The Sixth Congress of the PCE declared the urgent need to create a 'Social and National Liberation Front' as a tactical objective, advocating for a non-peaceful path towards Socialism without specifying the forms of struggle to be employed by the Party (whether legal, illegal, or clandestine).

The ideological struggles were further complicated by regionalist tensions exacerbated by CIA infiltration and the failure of a guerrilla project [es] on the banks of the Toachi River in the Santo Domingo de los Tsáchilas Province, culminated in the division of the party and the founding of the PCMLE.

He claimed the PCE was the "most organized force" of the Ecuadorian left in the 1960s, and that targeting the Communist Party of Ecuador was the CIA's primary objective in the country.

[13] The communist party was legally recognized until the 1960s, maintaining its existence but forming other political structures that represented it electorally, the first of these being the Popular Democratic Union.