During the last days of April, 1961, Anthony Galleta, a third year medical student attracted by the famous Rice Terraces, made a trip to the Mountain Province. While visiting Kiangan in Ifugao, the St. Joseph's Infirmary and Rest House, a charity clinic supported by the local Catholic Missions and ably conducted by a Belgian missionary sister who was also a nurse, called his attention. Galleta got interested and offered his medical services.

He returned to Manila to gather the interest of other possible volunteers and procured the things needed to continue on with his work. The UST Faculty of Medicine and Surgery responded favorably to his appeal and by the middle of May, he was back in Kiangan with Eduardo Jurilla and some equipment needed to set up a laboratory in the clinic.

By the time he returned to the Faculty of Medicine to enroll for the next school year, a conviction has taken root and an idea had been born in his mind - to send a medical team to Kiangan the next semestral vacation in response to the needed help by these mountain people. In school, he enlisted the enthusiasm of more medical students like Bibiano Ouano and successfully enlisted the official's approval of the UST Medical Association.

One year later, the MMI was established as an independent organization and was incorporated with the Securities and Exchange Commission.

Now, on its 43rd year of uninterrupted and dedicated service to the poor, the MMI  continues inspite of all the odds and difficulties to extend to the poor the much needed medical and surgical care charting provinces from Batanes to Jolo.