After leaving university, she worked in
general practice in the Melbourne suburbs of
Brighton and
Fitzroy, and in 1896 founded the
Victorian Medical Women's Society. She was a founding member of the
Queen Victoria Hospital in 1896 and was an honorary medical staff member at the hospital until 1910. Greig returned to the University of Melbourne to study for a Diploma of Public Health; when she completed the degree in 1910 she became the first woman at the university to do so. She went on to work for the
Victorian Department of Education as a medical officer, providing healthcare services for schoolchildren. She was promoted to the department's
Chief Medical Officer in 1929. From 1924 to 1925, she was a commissioner on the
Royal Commission on Health. She visited a number of countries to give talks on types medical and dental inspection, and published numerous articles and reports in the
Medical Journal of Australia. She was a lecturer in hygiene at the
University of Melbourne and at the Teachers' Training College from 1916 to 1939. ==Death and legacy==