For Shi'a Muslims, rituals and observances on Ashura consist primarily of public expressions of mourning and grief. Some Shi'as express mourning by flagellating themselves on the back with chains, beating their head or ritually cutting themselves. This is intended to connect them with Husayn's suffering and death as an aid to salvation on the Day of Judgment.

Passion plays commemorating the death of Husayn are also presented on Ashura. In London, around 3,000 Shi'a Muslims gather at the Marble Arch on Ashura for a mourning procession and speeches.

Many Shi'a make pilgrimages on Ashura to the Mashhad al-Husayn, the shrine in Karbala, Iraq, that is traditionally held to be Husayn's tomb.

Husayn's martyrdom is widely interpreted by Shia as a symbol of the struggle against injustice, tyranny, and oppression.

The regime of Saddam Hussein saw this as a potential threat and banned Ashura commemorations for many years. In neighboring Iran, the festival became a major political symbol during the Islamic Revolution, as also occurred in Lebanon during that country's civil war.

The 2004 (1425 AH) Shi'a pilgrimage to Karbala, the second since Saddam Hussein was removed from power in Iraq, was marred by bomb attacks that killed and wounded hundreds.