Welcome to our article answering your questions on if you should wear underwear underneath your swim trunks.

If you are looking specifically to see what to wear underwear under your board shorts, this will be more help to you.

Do You Wear Underwear With Swim Trunks

Do You Wear Underwear With Swim Trunks?

No, you do not wear underwear under your swim trunks or board shorts.

Swim trunks and all swimming apparel is made by brands whose sole purpose is to create the most effective pair of swimwear possible for you to enjoy. Swim trunks fabric will consist of polyester (can you shrink polyester,) nylon and spandex. The addition of mesh lining is added as well in certain types of shorts and brands.

These three fabrics are used because of how well they resist water, don’t bunch up to create skin rashes and countless other reasons.

When you put on cotton underwear (boxers, briefs, thongs or trunks) beneath your swim trunks, you negate the value of the swim trunks for water use. Your underwear will soak up the water, making it awkward to move your legs at certain angles and significantly increasing your risk of irritating the skin.

So, if you’re asking if you wear underwear with swim trunks to get the most out of your swim trunks, then the answer is NO.

However, if you ask because you feel more comfortable adding a tighter piece of clothing below your swim shorts, then YES.

Swim trunks vary in size and length. Board shorts are more extended and tend to have much more space between your legs and the fabric, while a pair of Euro-style swim trunks will be only a few inches long and hug your legs.

Comfort and confidence play a significant role in choosing what to wear to the beach.

If you feel more confident wearing boxers under your board shorts to the beach this summer, go ahead. You are not in the wrong for doing so.

Just be aware of those issues of chafing that may occur.


Guys wear underwear under their swim trunks because of this reason. Some men find it more comfortable to have a tighter piece of clothing surrounding their private parts.

When properly worn, swim trunks and board shorts are not meant to have anything under them. However, some guys wear underwear beneath their swimwear because they are more comfortable with the second layer of clothing.