Dr. Theodor C. von Brand, 78, a research parasitologist with the National Institutes of Health for 23 years before retiring in 1969, died Tuesday at Suburban Hospital after a heart attack.

Dr. von Brand joined the research staff of NIH in 1946 as a physiologist and parasitologist. He was named head of the Physiology and Biochemistry section of the Laboratory of Parasitic Diseases in 1947, the post he held until he retired.

During his years with NIH he wrote several books on parasite physiology and served on the Expert Advisory Panel on Parasitic Diseases of the World Health Organization.

He received the Department of Health, Education and Welfare's Superior Service Honor Award "for meritorious research on the chemical composition and metabolism of parasites."

Dr. von Brand was elected president of the American Society of Parasitologists in 1969.

He was a native of Ortenberg, Germany. He came to this country in 1936 after earning a doctorate in zoology at the University of Munich, a medical degree at the University of Erlangen, and after teaching parasitology at the University of Hamburg.

He worked as a research fellow at Johns Hopkins University and taught at both Barat College, Ill., and Catholic University before joining NIH.

He is survived by his wife, Margarethe, of the home in Bethesda; a son Theodor P., of Bethesda; a sister, Eleanore, of Germany, and three grandchildren.