It's a good idea to wash your pillowcase every few weeks so you're lying on a clean surface. But over time, your pillow itself can collect dust, moisture, and potentially develop mildew. Luckily, washing your pillow in your washing machine every 3-4 months can keep it nice and clean and prevent mold or mildew from having a chance to develop. Make it a habit to wash your MyPillow at least every 4 months to help it last longer. If you get sick and end up having to spend a lot of time in bed, you may want to wash your pillow after you feel better to get rid of any bacteria that may be on your pillow.