After the death of his father in 1891, Green relocated to Montreal to attend McGill University where he would obtain his medical degree.

[2] He later settled at Cranbrook, British Columbia, in the Kootenay Valley in 1899 to establish a medical practice.

[3] A partnership with Dr. James Horace King of Cranbrook which started in 1903 was described as a "cornerstone in local medicine", with modern innovations being in use at the time, two examples being the first x-ray machine in the city being purchased for their hospital and the use of automobiles within the practice.

[7] One of his sons, William Otis Green also became a doctor in the Cranbrook area, with whom he later shared a practice with.

[2][8] Frank W. Green died in 1953 of heart problems at St. Eugene Hospital in Cranbrook, which he had established.