Gordon started his training in medicine in New Zealand, earning M.B., Ch.B.(equivalent to USA’s M.D.) from the University of Otago Medical School. He completed his Master of Public Health (M.P.H) at the Harvard School of Public Health, Boston, Massachusetts and a Preventive Medicine residency at the US Centre's for Disease Control (CDC). Gordon worked in medical areas including surgery, accident emergency, and family practice in New Zealand, Australia, Papua New Guinea and the US, before specialising in public health, epidemiology and injury prevention and working at several esteemed US schools and centres. He is now a Professor of Epidemiology & Public Health at the University of Maryland School of Medicine, and core faculty National Study Centre for Trauma & EMS. He collaborates regularly with injury researchers in New Zealand and has received widespread recognition for methodological expertise in injury research, including the Excellence in Science Award from the American Public Health Association.