Underwear under swim trunks: yes or no?

It may seem like a simple question, but it sparks surprisingly much debate: do you wear underwear under swim trunks – or not? At the beach, by the pool or on holiday, you see it all the time. Some men swear by it, while others strongly advise against it. But what is actually the best choice?

In this blog, you’ll discover the advantages and disadvantages, the most common mistakes, and ultimately what the best choice is for comfort, hygiene and style.

Why do some men wear underwear under their swim trunks?

Wearing underwear under swim trunks often happens without much thought. Still, there are clear reasons behind it. Many men do it for extra support. Especially with swim trunks without a proper inner lining, underwear can provide a greater sense of security. Habit also plays a role. If you’re used to wearing underwear every day, you may feel “incomplete” without it.

Hygiene is also often mentioned as a reason. The idea is that an extra layer offers more protection, for example in public swimming pools. While these reasons are understandable, that doesn’t automatically make it the best option.

The downsides of wearing underwear under swim trunks

What many people don’t realise is that wearing underwear under swim trunks can actually cause problems. The biggest drawback lies in the combination of materials. Underwear is simply not designed to get wet and dry quickly. When you wear underwear under your swim trunks, it retains water. This results in a heavy, wet feeling that lingers.

It can also lead to skin irritation. Wet fabric rubbing against your skin increases the risk of chafing. Especially on warm days or when you’re moving a lot, this can quickly become uncomfortable.

From a hygiene perspective, it can even have the opposite effect. Wet underwear creates a warm, damp environment where bacteria can thrive more easily.

And finally, it affects the fit of your swim trunks. The extra layer can make them sit less neatly and feel less comfortable.

What about the inner lining of swim trunks?

Most swim trunks come with a built-in inner lining or mesh brief. This is specifically designed to provide support while drying quickly. In effect, this lining replaces the function of underwear. The material is lightweight, breathable and made to handle water.

If you’re wearing swim trunks with a good inner lining, an extra layer of underwear is unnecessary. In fact, it can reduce comfort.

When do people still choose to wear underwear?

There are still situations where men consciously choose to wear underwear under their swim trunks. For example, when the inner lining feels uncomfortable or is missing altogether.

With cheaper swim trunks, the quality of the inner lining can sometimes be lower, offering less support. In that case, underwear may seem like a logical solution. However, instead of adding an extra layer, it’s often better to look at the quality of the swim trunks themselves.

What is the best solution?

The best solution is surprisingly simple: choose swim trunks designed with comfort in mind. Modern swim trunks, such as those from Undiemeister, are made from quick-drying materials and feature smart details like a comfortable inner lining and a great fit.

This means you don’t need underwear. The swim trunks themselves provide everything you need: support, ventilation and comfort.

Still want extra reassurance? Then it’s better to choose specially designed underlayers suitable for water, rather than standard underwear.

Comfort, hygiene and style: finding the right balance

Wearing underwear under swim trunks may seem like a small decision, but it has a big impact on your comfort.

Without underwear, you benefit from:

• Faster drying
• Less risk of irritation
• Better ventilation
• A cleaner fit

With underwear, you create extra layers that trap moisture and limit your freedom of movement. The right balance lies in choosing high-quality swimwear designed to be worn without underwear.

Skip the underwear

So, underwear under swim trunks: yes or no?

The short answer: preferably not. While it’s understandable that some men do it, the disadvantages outweigh the benefits. Less comfort, more moisture and a higher risk of irritation make it far from ideal.

Instead, invest in a good pair of swim trunks that offer everything you need. That way, you’ll enjoy maximum freedom of movement, comfort and a fresh look – exactly as intended.