An official Bar Association directory shows that fees charged by Washington lawyers for the same services vary as much as 1,000 per cent.

One lawyer, for example, said he charges $50 to handle an uncontested divorce while another charges $500. Legal fees quoted for drafting simple wills ranged from $40 to $75, while the hourly charges listed by lawyers ranged from $20 to $110 - with the biggest, higher-priced firms keeping mum on their fee schedules.

For the first time in the nation, an official Bar Association directory lists lawyers' fees as well as their types of practice and their education in an attempt to help consumers choose an attorney.

"The primary goal of this directory is to take the mystery out of finding a lawyer and finding out how lawyers serve the public," said James M. McHale, who headed the Bar Association committee that put the directory together.

"It's the first time the ordinary person on the street can have a chance to find out nearly as much, and in some cases, more, about his or her lawyer as a corporate counsel can by consulting Martindale-Hubbell (a directory that lists and rates lawyers)."

The D.C. Bar's pace-setting directory already has attracted national attention from lawyers concerned with meeting the Supreme Courts recent ruling allowing attorney advertising.

R. Patrick Maxwell, the executive director of D.C. Bar, is scheduled to describe the directory at a special panel dealing with consumer guides and advertising at the American Bar Association meeting in Chicago this week.

While the directory is not meant to stop attorney advertising, it does provide an alternative means for lawyers to let the public know what services they provide and how much they charge.

McHale said the D.C. Bar directory is modeled after one planned for Northern Virginia by Consumers' Union but blocked by the state bar association. This type of directory for doctors as well as lawyers has been supported by consumer groups.

The D.C. directory lists about 600 of Washington's more than 20,000 lawyers, at least half of whom work for the federal government. Of the rest, experts estimate that between 6,000 and 8,000 practice national law - dealing with Congress and federal agencies - and have little to do with personal legal problems of Washington residents.

While none of Washington's largest and most influential firms are listed, these are the firms whose lawyers would be the lawyers the least used by people who live in the area. They are, however, the lawyers who charge the highest fees.

Even with the big firms not in it, the D.C. directory provides an unusually revealing glimpse of Washington's legal profession and its startling diversity.

Donald Madole, for example, represents victims of major airline disasters. Lawrence H. Mirbel helps universities get federal research grants. Jeffry Howard and Frank Sizemore specialize in cases of injury from poisonous chemicals. Nancy Dell Polikoff, who concentrates in women's rights, has written law review articles on the rights of lesbian mothers in custody disputes, a growing issue in the courts.

Their fees vary as much as their specialties.

Madole, whose suits against aircraft manufacturers and airlines on behalf of crash victims are credited with promoting air safety charges $100 for the first visit and gets an unlisted percentage of the settlement.

Mirbel charges from $50 to $75 an hour while Polikoff's fees range between $25 and $45 an hour.

Howard and Sizemore, who quit as top lawyers in the Environmental Protection Administration in 1976 in protest of what they viewed as agency stalling tactics on regulating poisonous chemicals, now earn $110 an hour representing people injured by the toxic substances. For other cases, where they are less expert, their fees drop to $70 an hour.

In more prosaic legal matters, David Scull listed his charges for an uncontested divorce at $50, but said that does not include his presence at the court hearing - which many attorneys feel is unnecessary.

Alexander Breuer, on the other hand, said he charges a minimum of $500 for handling the same uncontested divorce, though that includes attending the court hearing. His minimum fee for a contested divorce was listed as $1,000.

While there are no certified legal specialties, lawyers were able to list themselves in 18 different areas of practice - including personal and property injury law, consumer contract law, family law, immigration law, wills and general law. East listing cost a lawyer $10.

The D.C. Bar's board of governors approved the directory last year even though many members opposed it at the annual meeting.

The 200-page Bar Directory will be distributed to every public library in the District of Columbia and will be for sale by the Bar Association for $2 a copy.