An exorcism was a ritual used to expel a demon or ghostly spirit which had possessed a human or dwelling. This type of ritual was extremely dangerous for both the performer and the victim of the possession, sometimes resulting in the death of either individuals.
- After the demon Eyghon permanently possessed their friend Randall, Rupert Giles, Ethan Rayne, Deirdre Page, Philip Henry and Thomas Sutcliffe tried to exorcise the demon from Randall's body. However, they only succeeded in killing Randall.
- In 1998, when the spirits of James Stanley and Grace Newman unwittingly wreaked havoc in Sunnydale High, the Scooby Gang tried to exorcise James Stanley, forcing him to move on from this plane of existance. However, the exorcism was cut short by James' spirit.
- In 1998, the Old One Laibach of the Abyss possessed Drusilla while the Master possessed Angel. Xander Harris and Rupert Giles managed to exorcise Laibach while Willow Rosenberg managed to exorcise the Master after Buffy weakened him, casting a protection spell on him, Spike, and Drusilla so he couldn't possess any of the three of them again.
- In 1999, Angel and Doyle attempted to exorcise the ghost of Maude Pearson in order to stop the constant murders of the young women that lived in Pearson's former apartment. However, Mrs. Pearson's ghost was strong enough to resist the kind of ritual Angel attempted to perform.
- In 2000, when Julie, Graham Miller and the others are possessed by the apparitions of the Lowell House children's raw emotions abused by the Genevieve Holt accidentally released by Buffy and Riley while having sex when a party is thrown, Tara, Willow and Giles try to perform an exorcism in this place and the emotions.
- In 2000, Angel Investigations came face to face with an Ethros Demon, a powerful possessing demon with a penchant for mass murder, which had taken possession of a boy, Ryan Anderson. Angel Investigations sought the help of Father Fredricks, a known exorcist, only to discover that he had been killed in the process of exorcising another Ethros from a young girl. Wesley Wyndam-Pryce failed in expelling the demon, but Angel succeeded in completing the ritual. Afterwards, the demon took on physical form to recover its lost energy and Angel was able to kill it with an axe.
- In 2002, some kind of demon invaded the Summers home to stop Dawn Summers from seeing her mother and Dawn performed a spell to exorcise the demon from the house. Dawn succeeded in the exorcism, and given that blood splatterred the walls for a second afterwards, may have killed the demon when she exorcised it.
- In 2003, when Spike was ressurect like a ghost, Wesley Wyndam-Pryce suggested to Angel, Charles Gunn and Winifred Burkle to practice exorcism so that Spike could find peace.