Daphine Doster Mastroianni was born 7 October 1906 in Monroe, North Carolina, to a railroad worker and a nurse, and was raised in Gibson, North Carolina. She graduated from high school in 1923 and then attended the North Carolina College for Women (now the University of North Carolina at Greensboro), where she studied music. After graduating in 1927, Mastroianni worked as a music teacher at Cherryville High School and later Kings Mountain High School. She enrolled at John Hopkins School of Nursing in 1933 and graduated in 1936. She worked as a surgical nurse for three years in the operating room of John Hopkins and later Berea College Hospital in Berea, Kentucky. Mastroianni also did public nursing in Richmond, Kentucky, and Bowling Green, Kentucky.
Mastroianni joined the Army Nurse Corps in 1942 with a unit from Johns Hopkins Hospital, the 18th General Hospital. She went through basic training at Fort Jackson, South Carolina, and then served as a surgical nurse in New Zealand and Fiji from 1942 to 1945. In 1945 she was transferred to Calcutta, India. She returned to the U.S. and was briefly assigned to Fort Devens, Massachusetts.
Following her discharge, Mastroianni received her master’s in public health from the Minnesota School of Public Health. She worked for twenty-four years with the U.S. Public Health Service providing loans and personnel to aid states. During that time she worked for two years in the Arkansas Health Department. From 1952 to 1953 she served as acting dean of the school of nursing at the University of Arkansas while developing a four-year bachelor of science program in nursing. In 1992 she married Joe Mastroianni, whom she had originally met during World War II. Daphine Doster Mastroianni died on 3 August 2000.