Can I keep my piercings after becoming Muslim?

It depends on the piercing. Ear piercings for women are fine, and so are nose piercings according to many scholars. Most scholars say men shouldn't wear earrings, and body piercings like tongue or eyebrow rings are widely discouraged. You never have to worry about the holes themselves.

Adornment is allowed in Islam

Islam isn't against looking nice. The Quran asks:

قُلْ مَنْ حَرَّمَ زِينَةَ ٱللَّهِ ٱلَّتِىٓ أَخْرَجَ لِعِبَادِهِۦ "Say: Who has forbidden the adornment of Allah which He has produced for His servants?" Quran 7:32

Women: ears and nose

Women wore earrings in the Prophet's ﷺ time. When he encouraged the women to give charity after an Eid sermon, "some donated their ear-rings" (Sahih al-Bukhari 98). So ear piercings for women, including several in one ear, are allowed.

Nose piercings are a little more debated. Many scholars, especially from the Shafi'i and Hanafi schools, allow them for women where they're a normal kind of jewelry. Others are stricter. If yours is a simple stud, most scholars would say you're fine.

Men: earrings

The Prophet ﷺ cursed "those men who are in the similitude (assume the manners) of women" (Sahih al-Bukhari 5885). Because earrings were seen as women's jewelry, most scholars say men shouldn't wear them. If you're a man with an ear piercing, simply take the earring out. The hole will often close on its own, and even if it doesn't, there's no sin in a leftover hole. See Can Muslim men have long hair?

Also see Can Muslim men wear gold rings?

Tongue, eyebrow and other body piercings

Most scholars discourage piercings that don't have a tradition as normal jewelry, like tongue, lip, eyebrow or navel rings. Their reasons: they can harm the body, they change Allah's creation without a clear benefit, and they're often tied to a look you may want to leave behind. If you have them, removing the jewelry is the safest choice.

What about wudu?

Piercings don't affect your wudu. Just make sure water reaches the skin around them. Tight jewelry can be moved a little while you wash, the same way you'd move a tight ring.

And if you're wondering about other changes to your look, see Can I dye my hair?

Key points

Ear piercings for women are allowed.
Many scholars allow nose piercings for women.
Most scholars say men shouldn't wear earrings.
Body piercings like tongue or eyebrow rings are discouraged.

Tip: Take it one step at a time. Removing a piercing is easy, so don't stress about it on day one of your new faith.