The hospital has its origins in the visit to Tansen during the winter of 1951-52 of ornithologist Dr Robert Fleming (author of "Birds of Nepal") and his bird-watching expedition, which included amongst its members his physician wife Bethel and Dr Carl Fredericks. During their stay in Tansen they examined and treated many patients, even to the point of performing a bladder stone operation!

The local people invited them to come back and establish a hospital, and in 1954 permission was granted to the newly formed United Mission to Nepal (UMN) to begin health work in the Kathmandu Valley and Tansen. Initially Dr Fredericks worked from rented accommodation in the bazaar but, as the work grew, the decision was made to build a hospital on granted land in Bhusaldanda.

The hospital has continued to grow, long after the first building was opened in 1959, and now has 131 beds. The latest addition is the new maternity building which, as well as providing 15 maternity beds and 4 delivery rooms, also accommodates offices, the library, conference rooms, the new laboratory and on-call rooms. This has freed up space for improvements in the operating theatres (OT) and emergency department. All these alterations will be completed by 2006.

From the early days local people were trained as nurses for the wards, and paramedics for the Outpatient Department (OPD), OT, laboratory, pharmacy, etc. This tradition of training has continued. In the early years there were attached training schools which some time ago were handed back to the government. In 2000 the Tansen Nursing school reopened as a joint UMN and CTEVT venture, training certificate level nurses who use the hospital for clinical placements.

UMHT has also been accredited for some years to train MDGP's, and has more recently added to this Internships for new medical graduates, nurse anaesthetist training, and midwifery post-graduate and refresher courses. Also offered are short courses in OT management, dark room, and diagnostic ultrasound, and practical placements for physiotherapy students.