Physicians employed by the Group Health Association, the largest health maintenance organization in the Washington area, voted overwhelmingly yesterday to form a labor union to negotiate with GHA over their wages and working conditions.

The vote, 53 to 16 with eight challenged ballots and one void, constituted the first time that a group of Washington-area physicians have decided under the sanction of the National Labor Relations Act to form a union to represent them.

Unless challenged by the Group Health Association within five days, the vote will be certified by the National Labor Relations Board and the union then will represent the 97 physicians eligible for membership in the Group Health Association Physicians Association. The union is not affiliated with any national labor organization.

Harold Wool, president of GHA, said yesterday that the vote would not be challenged. "We have no problem with working with the physician organization," Wool said. "We look forward to a very constructive relationship."

GHA is a prepaid group medical practice association that provides medical care to more than 107,000 members in the Washington area. Physicians employed by the plan receive a salary from GHA rather than being paid fees for services and tests performed for patients.

The physicians were represented from about 1970 until 1976 by a medical council that was dissolved after its structure was found to be a violation of federal labor law. A subsequent attempt by GHA's physicians to organize themselves into a corporation to contract with the plan was turned down by the board of trustees.

The relationship of GHA's physician to the plan has been a major source of tension since the dissolution of the medical council. After GHA's board turned down the physicians' proposal to form a corporation, the group's executive director, Louis J. Segadelli, resigned. Segadelli had supported the physician corporation. The physicians have been attempting to find some way to influence decisions made by the GHA board, which is elected by the group's membership and which runs the organization.

Among the kinds of issues the physicians would like to have a voice in deciding, according to a spokesman, are such matters as how many patients they are required to see, the hiring of new physicians and the granting of study leave.

Dr. Norman Lieberman, president of the physicians' association, said in a statement released after the vote that his group was ready to negotiate and that it saw "no reason why agreement cannot be reached by March 1."

Lieberman said the vote was a "beginning," and that GHA physicians should "recommit themselves to work as a unified force to establish the physician as an integral part of the Group Health decision-making process, improve our working conditions, and devise better methods for keeping our patients healthy."