Free Shipping on Orders Over $50*

The SmartWool Microweight Boxer Brief harnesses the power of merino wool to give you extreme comfort even when you're training hard. Forget about bunching, soggy cotton briefs—these technical underwear use nature's best and mankind's smartest to keep you feeling good on the trail.

  • Merino wool breathes, helps regulate temperature, and its antimicrobial properties keeps these boxer briefs fresh
  • Elastane content enhances the fit and shape retention
  • Seamsoft thread in flatlock seams are smooth on your skin for irritation-free wear
  • Fully functional fly makes doing your business easier
  • Elastic waistband has wool terry-loop backing for extra next-to-skin comfort

Share your thoughts

What do you think of the

SmartWool Microweight Boxer Brief - Men's

? Share a...

Write a review

No file chosen

Rather attach a photo from another website?

Rather attach a photo from your computer?

    Add a:
  • Share a photo
  • Share a video


Product Fit:

Add Your Size

in cm

Height (ft, in):

Weight (lbs):

Size Purchased:

Only jpg, jpeg, png, gif or bmp files please.

Submit Cancel
Now review from the App. Download

Here's what others have to say...

5 5

Perfect Undies!

  • Familiarity: I've put it through the wringer
  • Fit: True to size
  • Height: 5' 10"
    Weight: 170 lbs
    Size Purchased: Medium

I've bought three pair of these and would like to replace all my underwear with them. They are expensive but well worth it. Perfect weight; I can wear them in any season. They are extremely comfortable. To me, the sizing seems to be spot-on (I'm 5'10", 170 lbs) but I have "thicker" thighs and hips thanks to 25 years of soccer. I bought Mediums. Overall, this underwear is exceptionally good. Highly recommended!

5 5

Do you tell people about your underwear?

  • Familiarity: I've put it through the wringer
  • Fit: Runs large
  • Height: 5' 9"
    Weight: 170 lbs
    Size Purchased: Small

Because I do. Like, all the time. These are amazing, insanely comfortable, and they harness the power of The Force to resist odor. It never ceases to amaze me how funk-free these remain. There are things I would change - the fly is dumb and pointless; the sizing is a little generous (I wear a small, and I'm a 32" in Levi's); they don't last forever; they're expensive - but I still keep buying them because they are the best underwear that has ever been made. Ever. I wear them every day, and they're the one item that I know I'm always going to pack for any trip.

5 5

First pair of merino boxers....

  • Familiarity: I've put it through the wringer
  • Fit: Runs large

An I'm impressed! If I could afford it I'd buy enough pairs to replace my current arsenal of cotton boxers!

5 5

Great comfort and performance at a price

  • Familiarity: I've put it through the wringer
  • Fit: True to size

Over the summer, I wore these SmartWool boxer briefs for several days in a row on many occasions without experiencing odor or irritation. Awesome!

Fit is comfortably loose and they move well beneath outer layers such as shorts or pants.

The wool is very thin, which concerned me a bit since I commute by bike to work and I wasn't sure how they would hold up. So far, after about two months, there is no sign of wear. I do have multiple pairs. And, yes, they have become what I wear almost every day.

I have tried Minus33 and Stoic, and I have...

I have tried Minus33 and Stoic, and I have had issues with "myself" randomly falling out of the fly in both brands. It feels as though there is not enough material in the fly, as if the panels are too narrow. Is it the same with the Smartwool?

Responded on

I have had that same issue with other brands, but not with these. These are by far my favorite. I would like to have a drawer full of them.

5 5

very light weight and comfortable.

  • Familiarity: I've used it several times
  • Fit: True to size

I use these for extended backpacking trips because they are very comfortable in hot or cold temperatures. They wick perspiration and don't smell even after several days of strenuous exercise. I even started wearing them as my everyday underwear because they are so much more comfortable than cotton or poly blends. They fit true to size and wash well in cold water.

5 5

Couldn't be Happier

  • Familiarity: I've put it through the wringer
  • Fit: True to size

I first bought a couple of these to wear on the trail, and they were so wonderful, I have been slowly purchasing more as they go on sale, and I wear them all day, every day. The first two I purchased 18 months ago, and have washed them (with Woolite, air dry) probably 15 times or more with no problems. They have held up well.

I like the longer legs, and the waistband has no chafe. I have a 36" waist, and the large fit well. Because of the wool, I can wear the same underwear for more than one day with no smell. I highly recommend them.

5 5

super comfortable

  • Familiarity: I've used it several times
  • Fit: True to size

Great fit to them, and the material is awesome as well. Very soft and light weight feeling. As Chris said, they do run up a little at times, but with the longer cut to them it really isn't that bad compared to others I've used. Overall they are a great, comfortable boxer brief with all the benefits of merino wool.

4 5

Suprisingly comfy

you might not think having wool on your bits and pieces would be comfortable, but smartwool made these even softer than their shirts. however, this softness makes it easier to the legs to ride up. i have bigger than average thighs, so maybe normal sized folks wont have the same issue. speaking of the legs, they have a nice, long cut that i like: not the short european model look that might as well be briefs (ice breaker).

other than that, they breathe well and dry quick. just remember, if the shorts or pants you're wearing don't breathe/wick well, that will limit the perforance of these boxers breifs.