Kay Mander was an innovative director of documentary films during the 1940s and early 1950s. She began her career working at the 1935 Berlin International Film Congress, after which she returned to Britain, where she found employment at Alexander Korda's London Films as an interpreter. Over the next few years she worked in publicity and dialogue continuity for both Fox-British and London Films, becoming one of the first women members of the ACT. Through informal contact with people in the documentary movement, she met the producer Arthur Elton, who offered her a job as a production assistant at the prestigious Shell Film Unit.
The first films that she herself directed in the early 1940's were technical films, instructional shorts on subjects such as the national fire service and the wartime homefront propaganda campaign. She directed Highland Doctor (1943) for Paul Rotha Productions about the government subsidised Highland and Islands Medical Service, followed by a recruitment film for the Ministry of Works, New Builders (1944) and several items for Rotha's wartime cinemagazine Worker and Warfront. She then moved to the Realist Film Unit where she co-directed one film, the documentary-drama Penicillin (1944). In early 1945, Mander and her husband, the documentary producer R.K. Neilson Baxter, established Basic Films, making Homes for the People (1945) and educational and promotional films for government and industrial sponsors. In 1948 and 1949, Mander made a series of French language films for the Ministry of Education including La Famille Martin (1949), which won a British Film Academy Award. Having both left Basic Films by the late 1940's, Neilson Baxter went to Indonesia to help set up a film unit and Mander joined him there in the early 1950's where she wrote and directed two short films: Mardi and the Monkey (1953) and The New Boat (1955). On her return to Britain, she directed a feature film for the Children's Film Foundation, The Kid from Canada (1957). Frustrated by the lack of directorial opportunities, she remained in the feature industry working in continuity on many films including The Four Horsemen of the Apocalypse (Vincente Minnelli, 1961), The Heroes of Telemark (Anthony Mann, 1965), Fahrenheit 451 (Francois Truffaut, 1966) and Tommy (Ken Russell, 1974) until the late 1990s.