Rugs should be professionally shampooed every 12 to 18 months, on average. This may be an overestimate. The frequency with which you should shampoo your rug depends on various factors, including the size of your household, the climate in which you live, and more. It's also likely that your rug will get dirty quickly if you live in a home with pets or children. Shampooing your rug three to four times a year is recommended.