Wilson's Men's Store, a Virginia-based chain that has been selling men's clothing in the Washington area since 1946, has filed for bankruptcy court protection after a summer of sharply lower sales.

Wilson's operates stores under three names, each with a different style of clothing: Wilson's, Contemporary Man and Town and Country. The chain has stores in Virginia, Maryland, New Jersey, Pennsylvania and North and South Carolina.

The firm was founded by the father of the current president and majority stockholder, David Lowenstein, who could not be reached for comment.

Wilson's joins a growing list of old-line Washington clothing retailers that have found themselves unable to compete against the national department and specialty stores that have moved into the region in the past decade -- stores that boast the latest styles, command the best location in shopping malls and spend heavily for merchandising and advertising. Just this summer, Garfinckel's and Arthur Adler closed their doors.

Wilson's, which has offices in Springfield, listed assets of $4.3 million and liabilities of $4.6 million. Maryland National Bank holds a large claim against the firm, said Windelin I. Lipp, an attorney for Wilson's.

Lipp said revenue had declined from $15.5 million in 1988 to $15.1 million in 1989, but she said she did not have precise figures on the "precipitous decline" of the last three months that led to the bankruptcy filing. "They will probably close a few stores and will emerge a healthy company," she said.