Antiseptic mouth rinse, often called mouthwash, is an oral hygiene product that claims to kill the germs that cause plaque, gingivitis, and bad breath. It is used by people interested in oral health and in not offending others with bad breath. It often comes in a strong mint flavor.

Proper use involves rinsing one's mouth with 20 milliliters of antiseptic mouth rinse two times a day. One then spits out instead of swallowing and rinses out the mouth.

Active ingredients can include thymol, eucalyptol, methyl salicylate, menthol, chlorhexidine gluconate and hydrogen peroxide. Ingredients also include water, and a significant amount of alcohol (around 20%). Because of the alcohol content, it is possible to fail a breath analyzer test after rinsing one's mouth.

Bacteria often become resistant to active ingredients in the mouthwash, lessening its effectiveness.