How To Get a Musty Smell Out Of a Mattress: Simple Steps That Work

If you’re wondering how to get a musty smell out of a mattress, you’re not alone. Musty odors are common, especially in humid rooms, older beds, or after a spill. The good news: in many cases, you can refresh your mattress at home with simple, low-cost steps.

This guide explains why mattresses smell musty, how to clean and deodorize them safely, and when it might be time to consider replacement.

What Causes a Mattress to Smell Musty?

A musty smell usually means moisture has been trapped in the mattress for a while. Common causes include:

  • High humidity or poor air circulation in the bedroom
  • Spills or accidents that weren’t dried fully
  • Sweat and body moisture over time
  • Storing the mattress in a basement, garage, or damp space

A mild musty odor can often be treated at home. However, strong, persistent smells may mean deeper moisture, staining, or even hidden mold, which is harder to fix.

How To Get a Musty Smell Out Of a Mattress: Step-by-Step

1. Air Out the Mattress

Start by giving the mattress as much fresh air as possible.

  1. Strip all bedding and mattress protectors.
  2. Stand the mattress up or leave it flat on a bed frame.
  3. Open windows and doors for cross-ventilation.
  4. If possible, place the mattress in indirect sunlight for a few hours.

Why this helps: Fresh air and light can reduce odor and surface moisture. Direct, intense sunlight for long periods can be harsh on some materials, so aim for short, indirect exposure.

2. Vacuum the Surface Thoroughly

Use a vacuum with an upholstery attachment to remove dust, skin cells, and debris that can trap odor.

  • Vacuum the top, sides, and seams.
  • Go slowly and make several passes.
  • Flip the mattress (if it’s designed to be used on both sides) and repeat.

Regular vacuuming is one of the easiest ways to keep musty smells from returning.

3. Use Baking Soda to Neutralize Odor

Baking soda is often used on mattresses because it can help absorb odors.

  1. Sprinkle a generous, even layer of baking soda over the entire surface.
  2. Gently rub it into the fabric with a clean, dry hand or soft brush.
  3. Leave it for several hours; many people prefer to leave it on for most of the day.
  4. Vacuum the mattress again to remove all residue.

For stronger smells, you can repeat this process once or twice.

4. Spot-Clean Any Damp or Stained Areas

If the musty smell started after a spill or accident, cleaning that area is important.

  • Mix a small amount of mild detergent with cool water.
  • Lightly dampen (do not soak) a cloth and blot the stained area.
  • Avoid saturating the mattress; excess water can make musty smells worse.
  • Blot with a dry cloth to remove as much moisture as possible.
  • Let the spot air-dry completely before putting any bedding back on.

📝 Tip: A small fan pointed at the mattress surface can help it dry faster.

5. Dehumidify the Room

Even if you follow every step for how to get a musty smell out of a mattress, the odor can return if the room itself stays damp.

  • Use a dehumidifier or an air conditioner to lower humidity.
  • Keep the room ventilated when possible.
  • Avoid pushing the mattress directly against exterior walls where air can’t circulate.

A drier environment helps your mattress stay fresher over time.

Is a Musty-Smelling Mattress Always Salvageable?

Not always. Some signs suggest that cleaning may not be enough:

  • The smell is very strong and doesn’t improve after airing, vacuuming, and baking soda.
  • There are visible dark spots that look like deep staining or possible mold.
  • The mattress feels damp to the touch even in a dry room.
  • The mattress is very old and has multiple odor sources.

In these cases, many sleepers decide it’s more practical to replace the mattress rather than continue trying to remove the smell.

How To Prevent Musty Smells in the Future

You can greatly reduce the chances of musty odors returning with a few simple habits:

  • Use a washable mattress protector to guard against spills and sweat.
  • Let your bed air out for a few minutes each morning before making it.
  • Wash sheets and bedding regularly, as recommended by fabric care labels.
  • Vacuum the mattress every few months.
  • Control humidity in the bedroom, especially in basements or humid climates.

These small steps help keep your mattress cleaner, drier, and more comfortable over time.

✔️ Quick Mattress Takeaways

Key points to understand about how to get a musty smell out of a mattress:

  • Musty smells usually come from trapped moisture combined with dust, sweat, or spills.
  • Start with fresh air and ventilation; open windows and let the mattress breathe.
  • Vacuum thoroughly to remove debris that can hold odor.
  • Baking soda is a simple, common way to neutralize smells on the mattress surface.
  • Avoid soaking the mattress when spot-cleaning; too much water can worsen mustiness.
  • Control room humidity to stop odors from coming back.
  • Persistent, strong smells or visible deep staining may mean the mattress is no longer practical to salvage.

With these steps, most people can noticeably improve or remove mild musty odors and keep their mattress fresher for longer.