How To Get a Bad Smell Out Of a Mattress: Practical FAQ Guide

If you’re wondering how to get a bad smell out of a mattress, you’re not alone. Odors from sweat, spills, pets, or just everyday use can build up over time. The good news: with the right steps, many smells can be reduced or removed without damaging your mattress.

This FAQ-style guide explains why mattresses start to smell, how to deodorize them safely, and what to avoid so you don’t make the problem worse.

Why does my mattress smell bad in the first place?

Mattresses naturally absorb moisture and odors over time. Common sources include:

  • Sweat and body oils
  • Spilled drinks or food
  • Pet accidents or dander
  • Smoke, musty rooms, or poor ventilation
  • New mattress off-gassing (a temporary “new” smell from manufacturing)

Because a mattress is thick and often covered with fabric and foam, smells can linger longer than they would on hard surfaces.

What should I do first when I notice a bad smell?

Before using any cleaner, identify the type of odor:

  • Musty or damp → may be related to moisture or mild mildew on the surface
  • Urine or strong organic odors → often from pets or accidents
  • Sour or sweaty → buildup of sweat and body oils
  • Chemical or “new mattress” smell → often from manufacturing and packaging

Then follow these initial steps:

  1. Strip all bedding (sheets, protectors, mattress pad) and wash according to the care labels.
  2. Check the mattress label for any cleaning warnings (for example, “spot clean only”).
  3. Air out the mattress by opening windows and, if possible, standing the mattress on its side in a well-ventilated room for a few hours.

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

1. Dry and air the mattress

Moisture often traps odors.

  • Let the mattress air out in a dry room.
  • Use a fan to improve airflow.
  • If the smell follows a spill, make sure the area feels completely dry to the touch before deodorizing.

2. Use baking soda for general deodorizing

Baking soda is commonly used to help absorb mild odors from fabrics.

  1. Lightly sprinkle a thin, even layer of baking soda over the entire surface.
  2. Gently rub it in with your hand to help it reach the outer fabric fibers.
  3. Leave it on for at least a few hours, longer if the smell is strong.
  4. Vacuum thoroughly using an upholstery attachment, going slowly to remove as much powder as possible.

You can repeat this process if the smell is still noticeable.

3. Treat specific spots (urine, spills, or concentrated odors)

For small areas:

  • Blot any fresh liquid with a clean, dry cloth first (don’t rub; that can push liquid deeper).
  • Use a slightly damp cloth with a small amount of mild soap to gently wipe the surface if your mattress care tag allows it.
  • Avoid soaking the mattress. Too much water can cause new odors or damage.

If a stain or odor is deep and persistent, general surface treatments may only reduce, not fully remove, the smell.

Are there smells that won’t come out easily?

Some deep or long-standing odors can be difficult to remove completely, such as:

  • Old urine that has soaked into deeper layers
  • Long-term smoke exposure
  • Strong mildew or mold odors from significant moisture

Home methods may lessen these odors but might not eliminate them. In such cases, reducing the smell and using a mattress protector and clean bedding may help make it less noticeable.

Is it safe to use vinegar, strong cleaners, or perfumes?

Many people consider household cleaners for how to get a bad smell out of a mattress, but there are risks:

  • Strong liquid cleaners can oversaturate the mattress and cause new odors or damage.
  • Harsh chemicals may affect fabrics and foams or leave their own strong smell.
  • Perfumes and sprays often only mask odors temporarily rather than remove them.

If you choose to use a mild cleaner:

  • Test a small, hidden area first.
  • Use as little liquid as possible.
  • Allow plenty of time to dry fully.

Always follow any guidance on the mattress label.

How long will it take for the smell to go away?

Timing depends on:

  • The type and strength of the odor
  • How long it has been there
  • Ventilation in the room
  • How often you deodorize and air out the mattress

Mild musty or “sweaty” smells may improve noticeably after one or two baking soda treatments and a full day of airing out. Deep or old odors can take multiple sessions and may still leave a faint scent.

How can I prevent bad smells from building up again?

Simple habits can help keep your mattress fresher:

  • Use a washable mattress protector to create a barrier between the mattress and spills, sweat, or pet accidents.
  • Wash bedding regularly to reduce odor transfer.
  • Air out the mattress occasionally by removing all bedding and letting it breathe.
  • Avoid placing the mattress in damp or poorly ventilated rooms whenever possible.
  • Clean up any spills or accidents promptly so they don’t soak deeply into the layers.

✅ Quick Mattress Takeaways

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

  • Start with airflow: Remove bedding and air out the mattress in a well-ventilated space.
  • Use baking soda: A light, even layer left for several hours and then vacuumed can help with general odors.
  • Treat spots gently: For spills or accidents, blot (don’t rub) and avoid soaking the mattress.
  • Be cautious with liquids and chemicals: Too much moisture or harsh cleaners can create new problems.
  • Some odors are stubborn: Deep, long-term smells may only be reduced, not fully removed.
  • Prevention helps most: Mattress protectors, regular bedding washes, and occasional airing out reduce future smells.

With patient, gentle cleaning and good ongoing care, most everyday mattress odors can be significantly reduced and kept under control.