Our Location Prima Pediatrics 18520 Via Princessa Canyon Country, CA 91387 Phone Number (661) 424-9000 Fax Number (661) 424-0808 If you are a current patient you can reach our after-hours on-call provider by dialing the above number and following the appropriate prompts. If this is an emergency, please dial 9-1-1. Our Exam RoomsTake a Tour