Dr. Byrd Stuart Levell, 68, professor of internal medicine at the University of Virginia Medical School, died Monday at the University hospital after a heart attack.

He had been on the faculty since 1940 and was chief of the division of hematology from 1946 to 1971. He also served at one time as chairman of the department of internal medicine and as assistant dean of the medical school.

Dr. Levell was born in Washington. He was a graduate of the Virginia Military Institute and the University of Virginia Medical School.

During World War II, he served with the Army medical corps in North Africa and Italy. He earned the Bronze Star.

Dr. levell was the author of more than 50 scientific papers and co-author of a textbook on hematology.

A room was named in his honor in the Health Sciences Library of the medical shcool. He had received a number of distinguished service awards.

He is survived by his wife, the former Nancy Butzner, of the home in Ivy, Va.; two daughters, Anne Levell Reynolds, of New Haven, Conn., and Lucie Levell Vogel, of Charlottesville; a son, Dr. Byrd Stuart Jr., of Atlanta, Ga., two sisters, Mrs. Henry D. Blake, of Culpeper, Va., and Mrs. Charles J. Blake, of Wilmington, N.C., and six grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the University of Virginia Medical Alumni Foundation to endow a chair in his name.