Campbell is a New Zealand trained ENT surgeon, with a main interest in nasal and sinus surgery. He maintains a general ENT practice through the public hospitals.

Campbell gained his FRACS in 2008 following training throughout the country. He has since worked as a consultant at North Shore, Auckland and Hastings Hospitals, before settling in Wellington with his family. He spent a dedicated year as a rhinology fellow in Auckland in 2010, which included training in its extended applications (complex and revision sinus surgery, rhinoplasty, orbital and anterior skull base surgery).