In Christian churches, Ash Wednesday is the first day of the penitential season of Lent, so called this ceremony for it is the ceremony of placing ashes on the forehead as a sign of penitence. In the Roman Catholic Church, ashes obtained from burned palm branches of the previous Palm Sunday are blessed before mass on Ash Wednesday. The priest places the blessed ashes on the foreheads of the officiating priests, the clergy, and the congregation, while reciting over each one the following: "Remember that you are dust, and unto dust you shall return".

Lent is a period of fasting and penitence in preparation for Easter. The length of the Lenten fast, during which observant eat sparingly, was established in the 4th century as 40 days. The 40-day period begins on Ash Wednesday and extends, with the omission of Sundays, to the day before Easter.

On Maundy Thursday there is a special celebration in Verges (Gerona). A macabre dance is performed by men dressed as skeletons.

In Spain, the saints or pasos are carried through the streets by specially chosen people, some of whom wear the traditional hooded costumes of the community.