Mühlpfordt studied medicine, literature, and art history at Freiburg (1912), Munich (1912–13), and the Albertina (1913–14).
During World War II Mühlpfordt served as a physician (Stabsarzt and Oberstabsarzt) in the Wehrmacht from 1939 until his discharge for health reasons in 1944.
From January 1945 until April he tended to refugees in Pillau (Baltiysk) and the Vistula Spit during the evacuation of East Prussia.
Aside from his medical practice, Mühlpfordt also wrote about the local history of East and West Prussia, especially his hometown Königsberg, contributing to newspapers, journals, and his reference works.
He also wrote a novel about Wilhelmine Königsberg, Der Goldene Ball, Ein Familienroman unserer Zeit.