To cure vampirism in The Elder Scrolls IV: Oblivion, you have two main scenarios depending on how long it has been since you contracted the vampirism disease, Porphyric Hemophilia:

If Less Than 72 Hours Have Passed

You can cure vampirism easily before it fully takes hold by removing the disease using any of these methods:

• Drink a Cure Disease potion
• Cast a Cure Disease spell
• Eat a food item with the "Cure Disease" effect such as Mandrake Root or Shepherd's Pie
• Pray at a Wayshrine, Chapel, or Temple

If you do this within 3 in-game days, you will never turn into a vampire

If More Than 72 Hours Have Passed (You Are a Full Vampire)

Once vampirism has fully set in, curing it becomes more involved. You have two main options:

1. Complete the "Vampire Cure" Quest

• Start by speaking to Raminus Polus at the Arcane University in the Imperial City.
• He will direct you to Count Janus Hassildor in Castle Skingrad.
• The Count will send you to Melisande, who lives near Cheydinhal.
• Melisande will cure your vampirism if you bring her five empty Grand Soul Gems.
• After completing her task, you receive a recipe for a Cure Vampirism potion to cure yourself permanently.
• Note: After curing, you cannot become a vampire again without cheats

2. Use the Font of Renewal (Easiest Method with Vile Lair DLC or in

Remastered)

• The Font of Renewal is located in Deepscorn Hollow, an island southeast on the map.
• Collect ore from veins around a pool and activate the stone pillar in the pool.
• This instantly cures vampirism.
• This method is much faster and simpler than the quest.
• Using this method locks you out of the Vampire Cure quest.
• After curing, you cannot become a vampire again without console commands

Additional Notes

• If you cure vampirism by any method, you permanently lose the ability to become a vampire again in that playthrough.
• If you want to skip all in-game steps, you can also use console commands to add a Cure Vampirism potion directly to your inventory and drink it to cure instantly

In summary, if you catch vampirism early, cure it like any disease. If you are fully a vampire, either complete the Vampire Cure quest or use the Font of Renewal in Deepscorn Hollow for a quick cure