Mary Louise Gladish received a bachelor's degree in Home Economics at the University of Tennessee, an master's degree in Public Health at the University of North Carolina, and another master's degree in Education from the University of Chicago. She was a Swift Fellow in Nutrition at Harvard and later became Associate Professor of Health Education at East Tennessee State University.

Medical problems forced Gladish to abandon teaching for the field of medical librarianship. She earned a third master's degree in Library Science at Peabody College. She began work at Vanderbilt in 1964 as the Medical Library's first and only full-time reference librarian. Gladish worked with Eleanor Steinke, then Diretor of Vanderbilt Medical Library, on a posthumous revision and enlargement of Eileen Cunningham's Classification for Medical Literature, as published in its fifth edition in 1967. She was appointed to the MLA Curriculm Committee in 1970, taught the Special Libraries course at Peabody College, and later established the Health Sciences Librarianship course there. Gladish retired in 1982 and passed away in 1993.