Best Way to Remove Mold, Mildew & Grime From the Underside of a Shower Curtain

For most washable fabric or plastic shower curtains, the best approach is to wash the curtain first, then treat any remaining mildew spots rather than relying on harsh chemicals alone.

What You’ll Need

• 1 cup white vinegar
• ½ cup baking soda
• Mild laundry detergent
• Old toothbrush or soft scrub brush
• Washing machine
• Clean towels

Step-by-Step

1. Remove the shower curtain and take off any hooks or rings.
2. Rinse the underside with warm water to loosen soap scum and grime.
3. Apply a little liquid laundry detergent directly to heavily soiled areas. Gently scrub with a soft brush.
4. Put the curtain in the washing machine with 2–3 old towels. The towels provide gentle scrubbing during the wash.
5. Add your normal amount of laundry detergent.
6. Add 1 cup of white vinegar to the rinse compartment or during the rinse cycle.
7. Wash according to the curtain’s care label, preferably using warm water if permitted.
8. For persistent mildew stains, make a paste from baking soda and a small amount of water, gently work it into the affected area, then rinse thoroughly.
9. Hang the curtain back up immediately and allow it to air-dry completely.

⚠️ Important: Don’t Mix Cleaning Chemicals

Never mix vinegar with chlorine bleach. The combination can produce dangerous chlorine gas.

If your curtain is white and bleach-safe, chlorine bleach can sometimes be used instead of vinegar, following the product and curtain-care-label directions—but don’t use vinegar in the same cleaning cycle.

For Stubborn Black Mold

If black spots remain after washing, they may be deeply embedded in the material. For an inexpensive plastic liner, replacement is often safer, easier, and more effective than repeatedly trying to remove deeply established mold.

Keep It From Coming Back

After showering:

• Spread the curtain fully open so it dries faster.
• Run the bathroom exhaust fan during and after showers.
• Leave the fan running for around 20–30 minutes afterward.
• Clean the bottom edge of the curtain regularly.
• Keep the bathroom as dry and well-ventilated as possible.

Best overall method: detergent + washing-machine cleaning for grime, followed by appropriate mildew treatment if needed, and thorough drying.