Scrape up any pizza toppings with a butter knife. Blot excess tomato sauce with a clean cloth, if necessary.
Select a cleaning agent. Club soda or a mixture of dish soap and cool water work well for fresh pizza stains. For pizza stains that have been allowed to set, try preparing a solution of 1 tbsp. of ammonia to ½ cup of cool water.
Apply your chosen cleaning agent directly onto the stained area. Blot until the stain disappears from the carpet.
Sponge the stained area with fresh water to remove the cleaning agents.
Blot the area once more to dry it.