Doris Detre Nichols, 59, a retired economist with the Department of Agriculture and a native Washingtonian, died of cancer last Friday at Commonwealth Doctors Hospital.

Mrs. Nichols had worked for the old Tariff Commission before joining the Agriculture Department about 1948. A specialist in international finance and the economics of cotton marketing, she often represented the department on government teams during trade negotiations abroad.

She retired in 1965, and subsequently worked as a private consultant in international economics to a number of businesses here.

Her father, Dr. Laszlo Detre, was a bacteriologist in Hungary before joining the U.S. Public Health Service in 1932 as a senior immunologist, and Mrs. Nichols' early years were spent traveling between Budapest and Washington.

She earned a bachelor's degree in economics from American University here and a doctorate in economics from the University of Vienna in Austria.

During World War II, she was asked by Eleanor Roosevelt to assist in community and civil defense projects, and traveled the country with Mrs. Roosevelt in this capacity for about two years. Mrs. Roosevelt had recruited her services after Mrs. Nichols had wired the president's wife that she, too, wished to help in the U.S. war effort.

Mrs. Nichols was a member of the Fairfax Hunt and Great Falls Episcopal Church.

She is survived by her husband, Charles Kelsey Nichols, of the home in Great Falls, Va.; a daughter, Ann McMann, of Tallahassee, Fla.; two sons by a previous marriage. Roger Rafler, of Silver Spring, and Randy Rafler, of Manassas; another son, Charles E. Nichols, of Edinburg, Va., and a sister, Gwendolyn Cafritz, of Washington.

The family suggests that expressions of sympathy be in the form of contributions to the American Cancer Society or to Great Falls Episcopal Church.