Brian Bracegirdle was born in 1933 in Macclesfield. After leaving school he worked for ICI in the dyestuffs division. Whilst working, Bracegirdle studied for a BSc at the University of London. In 1958 he left ICI to become Biology Master, Erith Grammar School, where he worked until 1961. He then joined St Katharine’s College, London, 1961–64 before becoming the Head of the Departments of Natural Science and Learning Resources at the College of All Saints, London, 1964–77.

Bracegirdle began his writing career in the 1960s, publishing books and articles on photography for life sciences, various scientific topics, on the history of science and medicine, as well as the Industrial Revolution. Bracegirdle was an expert photographer, and often illustrated his own works.

During his period of teaching, Bracegirdle continued his studies, obtaining a PhD in 1975 from University College London. The following year the Science Museum was seeking a Keeper for the newly established Wellcome Museum of the History of Medicine, and recruited Bracegirdle to the role.

As Keeper, Bracegirdle swiftly established his new department, hiring staff. He launched a project to have them register between 100,000 and 165,000 objects using newly developed computer techniques. Bracegirdle also created a library of medical works, created an acquisition policy, and established two galleries illustrating the history of medicine. Bracegirdle was particularly interested in the 'Glimpses of Medical History' gallery set up to display Sir Henry Wellcome's collection, and was the first permanent medical display in the Science Museum. The gallery remained a fixture of the museum from its opening in 1980 until 2016.

Changes of personnel at the Science Museum led Bracegirdle to take early retirement in 1987. However, he remained at the museum in the capacity of a Fellow, and undertook a project to catalogue the vast microscopy collection. 'A Catalogue of the Microscopy Collections at the Science Museum, London' was made available on CD-ROM in 1989. With the completion of the project, Bracegirdle retired.

Bracegirdle remained intellectually active in retirement. He became an Honorary Research Fellow in the History of Science at Imperial College from 1990–93 and edited the Quekett Journal of Microscopy between 1998 and 2012.

Brian Bracegirdle retired to Cheltenham, where he died in December 2015.