Preston E. Teal, 68, the owner and president of Woodmoor Real Estate Inc. of Silver Spring for the past 10 years, died at his home in Kensington Sunday of amyotrophic lateral sclerosis, also known as Lou Gehrig's disease.

Mr. Teal, who was born and reared in Pittsfield, Mass., moved to Washington in 1934. He got a job with the Library of Congress and remained there until World War II, when he served in the Army. After the war, he returned here and joined the General Acceptance Corporation, a finance company, and worked for it in Washington and Indiana.

He began his career in real estate in 1959. He worked for a number of companies in the Maryland suburbs until 1969, when he joined Woodmoor. Two years later, he became owner and president of the business.

Mr. Teal was a member of the Montgomery County Real Estate Board and a member of the board of United Cerebral Palsy of Prince George's County, Inc.

Survivors include his wife, Bernadine, of Kensington, a daughter, Judy Myers of Olney, three sisters, four brothers, and four grandchildren.

The family suggests that expressions of sympathy be in the form of contributions to the ALS Foundation, Sherman Oaks, Calif.