Find Your Store
Home Page

Cart, contains 0 items

When autocomplete results are available use up and down arrows to review and enter to select. Touch device users, explore by touch or with swipe gestures.
Expert Help
Earn Rewards

Merino 150 Boxer Brief - Men's

3.62 out of 5 stars
50 Reviews

Out of Stock

Don't worry though, we have a lot more Men's Underwear in stock than that.

Shop Similar Products

Merino 150 Boxer Brief

While comfort is a relative experience, it's pretty clear that such an experience can be universally achieved by way of wearing, well, comfortable underwear—much like the SmartWool Men's Merino 150 Boxer Brief. This boxer brief features Smartwool's lightest merino wool which regulates your temperature and manages moisture with ease. The design includes a fully functional fly for your convenience, while the smooth waist band and flatlock seams prevent chafing or hot spots. So no matter if your day takes you to the trails, gym, or simply to the office, the 150 Boxer Brief assures adaptive performance and steadfast comfort.


  • Maintain comfort with this boxer brief
  • Merino wool wicks away moisture and dries quickly
  • Fully functional fly for your convenience
  • Smooth waist band and flatlock seams prevent hot spots
  • Item #SWL00RF
87% merino, 13% nylon
boxer brief
[medium] 6.5in
natural attribute of wool
Manufacturer Warranty
2 years

Overall Rating

3.5 based on 50 ratings

Review Summary

1 Stars - 13 reviews
2 Stars - 3 reviews
3 Stars - 2 reviews
4 Stars - 4 reviews
5 Stars - 28 reviews

Fits True To Size

Screen reader users: the following list provides a visual scale to illustrate the product fit. Please refer to the heading above for the fit type in text.
Runs smallTrue to sizeRuns large

What do you think about this product?


Selecting an option will reload the available reviews on the page
1 out of 5 stars

September 25, 2022

Horrible durability

I've used it several times

All three pairs I bought developed large holes in the crotch within a few short months.

Tyeler R
5 out of 5 stars

September 22, 2021

Worth the extra cost

I've put it through the wringer

I have tested a couple pairs over the Pacific Crest Trail and was very satisfied. Despite use with heavy activity for a couple weeks between washes, odor was never an issue. Good breathability, durability, and comfort. The merino is worth the extra expense for any backpacking or extended traveling over a cheaper synthetic.

Jeremy S
4 out of 5 stars

August 3, 2021

Comfortable and odor resistant

I've used it several times
Size Bought:
5' 10"

These boxer briefs are pretty comfortable and decently odor-resistant. I wore them during a recent backpacking trip and they performed well. I can't attest to their durability yet, but so far so good. I would pick up a couple more pairs during sales, but probably not for full sticker price.

Abe T
5 out of 5 stars

March 31, 2021

Lots of ones yet!

[This review was collected as part of a promotion.] I have about 10 pairs of these Merino 150 Boxer Brief from several years of models. These are for sure the softest and least itchy feel for me so far. I am a 32-33ish waist and typically wear Medium (sometimes Large) in boxers and shorts. These I am a true Large. The waistband is comfortable and stylish. They sit at a great length for my comfort. I wear these for all sorts of activities, from working 8-9 hours a day with an 1 commute to hiking 8 miles on trails. They regulate temperature well. I truly love the new design with the Plant Based Dye and details. Will be bragging about these for a while! #SmartwoolLove

Josh K

Originally reviewed on

5 out of 5 stars

March 29, 2021

Makes me do laundry more often!

[This review was collected as part of a promotion.] I've had one pair for only a few week now so I can't say how they'll hold up for durability but I do know they're my go to pair first out of the laundry pile. I even found myself doing an early laundry day before a cold ice climbing outing so I could use these. I've used these ice and rock climbing hiking and hanging out inside. They feel great! No bunching under a harness in the waist or legs. Comfortable all day casual wearing too.. I'm actually wearing them now as I write this. #SmartwoolLove

Eric W

Originally reviewed on

5 out of 5 stars

March 10, 2021

I plan to purchase additional briefs in the future

I am happy with the fit and comfort. I still need to see how the brief's feel during a Texas summer. I have been wearing the brief's in 20-75 degree weather and do not notice that I am wearing the anything. Some have mentioned the larger waist band, but I have not noticed any issues.


Originally reviewed on

4 out of 5 stars

March 3, 2021

I purchased for a trip and would buy again.

Using it for adventure travel

June s

Originally reviewed on

1 out of 5 stars

November 1, 2020

Would not buy again

Bought Smartwool shirts and underwear, Darn Tough socks for daily walks. Shirts and socks have held up fine over the past 6 months. The underwear have worn through. For money paid, quality of underwear is very poor.


Originally reviewed on

1 out of 5 stars

April 30, 2020

Very disappointed. Bought 2 pairs and both have holes

I bought two pairs of the Merino 150 briefs and I loved them. They fit great functioned awesome, but that's where the good stops. Less than 1 year of ownership of casual use and the waistband starts to come unthreaded. I still wore them because I paid so much for them. Then come the holes the same pair shredded on the inseam. To say the least I was very disappointed. Now my second pair is doing the same thing. Shredding on the inseam. If less than 1 year is all you get out of a premium purchase like that I couldn't possibly recommend anyone get these. I like them, but I'm not going to spend more money on clothing that wears out after less than 12 months.


Originally reviewed on

5 out of 5 stars

January 8, 2020

I would buy again.

[This review was collected as part of a promotion.] Purchased as a gift for my boyfriend. He loves it. He wears it to go climbing outside.


Originally reviewed on