Inez Posey Gillespie, 86, a native of La Plata, Md., and a resident of Washington for almost 40 years, died at Sibley Memorial Hospital Wednesday shortly after she was injured in an automobile accident.

Mrs. Gillespie was a passenger in a vehicle driven by her daughter, Mary Howard Critchell, of Washington, when it and another vehicle collided at 47th Street and Massachusetts Avenue NW, according to D.C. police.Mrs. Critchell was hospitalized with injuries, police said.

Mrs. Gillespie grew up in Maryland. She served in France with the Red Cross in World War I. In 1924, she married Julian Edgeworth Gillespie, an American diplomat, and accompanied him to Istanbul, Turkey, where they lived until his death in 1939.

Mrs. Gillespie had lived in Washington since then. In 1971, she received the medal of the Turkish Red Crescent Society because of her interest in that country.

She was a member of the Colonial Dames and of the Descendants of the Lords of Maryland Manors. She also belonged to DACOR.

In addition to Mrs. Critchell, survivors include another daughter, Ann Kelly, of Washington, a son, Julian Jr., of Sumner, Md., 10 grandchildren and one great-grandson.

The family suggests that expressions of sympathy be in the form of contributions to the Little Sisters of the Poor, 601 Maiden Choice La., Baltimore.