Born and raised in a small town in the Philippines, Ramon showed dancing and musical talents at an early age. His parents, Florentina and Salustiano Sison, conservative landowners with substantial landholdings, encouraged him to become a doctor but discouraged him from the uncertainties of pursuing a musical or showbiz career. He followed his parents' advice. However, he could not refuse when offered a role in a movie and later opportunities to play the piano and act in radio and television programs while attending the University of the Philippines pre-med and medical school in Manila. After obtaining his medical degree in 1955 he went to Georgetown University for post-doctoral specialization. He practiced medicine in the mid-West for nine years where he played piano in a jazz band with medical colleagues in Springfield, Illinois. During those years he also played double bass with the conservatory symphony of MacMurray College in Jacksonville, Illinois. Shortly after moving west to Beverly Hills, California, with no intention of pursuing an acting career in Hollywood, he found himself one day in 1976 playing the role of medical officer opposite Gregory Peck in a hospital scene of "MacArthur". Since 1976 he has appeared in a number of movie, TV and equity-waiver stage productions in Hollywood. He has been active as president or member in many community, civic and professional organizations in Southern California.

• Troop Beverly Hills (1989)