Sears' residencies were taken at Harvard Medical School's Children's Hospital in Boston and the Hospital for Sick Children in Toronto. He is an Associate Clinical Professor of Pediatrics at the University of California, Irvine, School of Medicine.
He is a medical and parenting consultant for BabyTalk and Parenting magazines and the pediatrician on the website Parenting.com According to his biography, he has been a guest on more than 100 television shows including: 20/20, Donahue, Good Morning America, Oprah Winfrey, CBS This Morning, CNN, Today Show and Dateline.
Sears and his wife Martha have eight children, one of whom has Down Syndrome. Three of the children have also become doctors, "Dr. Jim" (the oldest), "Dr. Bob" (second oldest), and "Dr. Pete." A fourth son, Matt, is currently studying medicine at UC Irvine.
According to his website, in 1997, Sears underwent major surgery for colon cancer, followed by radiation therapy and chemotherapy.
Dr. Sears has used his website to promote a nutritional supplement known as Juice Plus. In 2005, the company behind the product, National Safety Associates, used his testimonials to promote its product and included ad copy which implied that the "Juice Plus+Gummies" product was low in sugar, and a nutritional alternative to fruits and vegetables. This claim resulted in consumer complaints to the Better Business Bureau's national advertising division, and the BBB issued a complaint that NSA's claims were misleading. As a result, NSA promised to modify its ads.
As of 2007, Sears lives with his family in San Clemente, California, where he has a private medical practice with his sons.