David W. Louisell, the Elizabeth J. Boalt Professor of Law at the University of California at Berkeley, who practiced law in Washington in the 1940s, died Sunday in Berkely after a stroke. He was 63 years old.

A native of Duluth, Minn., Mr. Louisell received his bachelor's and law degrees from the University of Minnesota in 1935 and 1938. He also taught law at the University of Minnesota from 1950 to 1956.

Before teaching, Mr. Louisell practiced in Washington, first for a firm then named Covington and Burling. Acheson & Schorb (1941-46) and then for his own firm, Spencer and Louisell (1946-50).

From his job at the University of Minnesota, Louisell became a professor of law at Berkeley. He was named to toe Boalt professorship in 1964.

In addition to writing several law books, Mr. Louisell served on the National Committee for the Protection of Human Subjects of Biomedical and Behavioral Research beginning in 1974. He also sat on the Supreme Court Advisory Committee from 1960 to 1970.

Surviving are his wife, Dorothy L., of the Berkeley home; two sons, William D. of Berkeley and Mark N. of Charlottesville, Va.

The family asks that any contributions made in Mr. Louisell's memory be donated to Hanna Boys Center, P.O. Box 100, Sonoma, Calif. 95476.