Stain-removal pretreatment products help remove oil-based stains such as this. If stain removal pretreatment products are unavailable, apply heavy-duty liquid detergent, or powdered detergent mixed with water to make a runny paste, to the stain. Work the detergent into the stain. Diesel fuel makes clothing more flammable than normal. Use detergent-based stain removers, not solvent-based ones. Air clothing thoroughly; do not place a garment in a dryer if you can still smell fuel.

After pretreatment, wash the garment in hot water (if safe for the fabric) using the recommended amount of detergent for a regular laundry load. Rinse and inspect before drying. Air dry. Repeat this treatment if removal is incomplete.