[2] The deaths were described as the pivotal event in the Iranian Revolution that ended any "hope for compromise" between the protest movement and the regime of Shah Mohammad Reza Pahlavi.

On 8 September, thousands gathered in Tehran's Jaleh Square for a religious demonstration, unaware that the government had declared martial law a day earlier.

It is also believed that Black Friday played a crucial role in further radicalizing the protest movement, uniting the opposition to the Shah and mobilized the masses.

[21] According to the historian Abbas Amanat:[22] The clerical activists, backed by the Qom marja's, capitalized on the Jaleh Square massacre to paint the regime as brutal and illegitimate.

Aided by a rumor-mongering machine that became fully operational in the absence of reliable media and news reporting, the number of casualties, the “martyrs” on the path of Islam, was inflated to thousands, and the troops who opened fire on them were labeled as Israeli mercenaries who were brought in to crush the revolution.The events triggered protests that continued for another four months.

[31][page needed][32] French social theorist Michel Foucault first reported that 2,000 to 3,000 people had died in Jaleh Square, and he later raised that number to 4,000.

[20] Since the 2000s, some former Pahlavi Iranian politicians have suggested greater ambiguity in the situation, in particular the presence of Palestinian guerrillas in Iran, who they believe were agitators.

[36][37][page needed] In 1978 shortly after the massacre, the Iranian musician Hossein Alizadeh set Siavash Kasraie's poem about the event to music.