Dr Lee served for 13 years in the Armed Forces Health Services and retired as Consultant & Head of the Department of Diving and Hyperbaric Medicine.

In 1997, after having completed his post-graduated Diploma of Diving & Hyperbaric Medicine (Australia), Dr Lee was appointed head of the newly formed Diving & Hyperbaric Medicine Department at the Lumut Armed Forces Hospital, where his duties included providing Medical Support for Military Diving operations and advising the Royal Malaysian Navy on the medical aspects of the Diving Programme.

Dr Lee was then in private practice providing the first civilian consultant hyperbaric and occupational medicine services from January 2002, and under a joint-venture agreement, became the Medical

Director for Hyperbaric Health Australia in Malaysia. Later, Dr Lee went on to form Hyperbaric Health Asia, a subsidiary company of Hyperbaric Health, Australia to provide Diving & Hyperbaric Medical Services in the Region.

Since then, Dr Lee has been active in providing Consultancy service and Medical Support Hotline to several commercial diving companies and tunnelling projects.

In 2017, Dr Lee was invited to be a Corresponding Member of the Diving Medical Advisory Committee. Dr Lee is also a former president of the Asia Hyperbaric and Diving Medical Association (AHDMA). In 2020, Dr Lee joined the Team of Doctors managing the DAN Emergency Hotline in Malaysia, also servicing Indonesia.