Hi mama! Honestly, I'm not 100% sure kung compatible talaga ang Pigeon bottles sa Avent sterilizer kasi different brands sila, pero a few of us tried mixing brands and it usually works, the issue is more kung paano sila fit sa slots nang safe rather than compatibility mismo. I'd suggest checking the dimensions ng Pigeon bottles against your Avent sterilizer's manual, or you could ask sa Pigeon customer service directly kasi sila ang makakaalam ng exact measurements, better safe than sorry, diba!