Moore, the filmmaker whose targets have included General Motors (''Roger & Me''), the gun lobby (the Oscar-winning ''Bowling for Columbine'') and President Bush (''Fahrenheit 9/11''), has now set his sights on the health-care industry, including insurance companies, HMOs, the Food and Drug Administration - and drug companies.

At least six of the nation's largest companies already have issued internal notices to their work forces, preparing them for potential ambushes.

''We ran a story in our online newspaper saying Moore is embarking on a documentary - and if you see a scruffy guy in a baseball cap, you'll know who it is,'' said Stephen Lederer, a spokesman for Pfizer Global Research and Development.

In September and October, GlaxoSmithKline, the second-largest in retail sales, as well as AstraZeneca and Wyeth, sent out Moore alerts, instructing employees that questions posed by the media or filmmakers should be handled by corporate communications. Heavyweights Sanofi-Synthelabo and Aventis Pharmaceuticals each sent similar memos before their recent merger. Merck & Co., Abbott Laboratories, Eli Lilly & Co., Bristol-Myers Squibb, Novartis Pharmaceuticals and Teva Pharmaceutical Industries send periodic messages about dealing with the media but haven't singled out Moore by name. Johnson & Johnson declined to comment.

Moore's project is only the latest bit of bad news for the beleaguered industry. Popular - and lucrative - drugs such as Vioxx, Celebrex and Aleve have been linked to cardiovascular problems, and the possibility of lawsuits is looming. Canada is undercutting U.S. drug prices, and health budgets are being slashed. And then there is increased scrutiny by the FDA, whose oversight of the drug industry and its relationship to it is raising many questions.

''We have an image problem - not only with Michael Moore, but with the general public,'' said M.J. Fingland, senior director of communications for the Washington, D.C.-based Pharmaceutical Research and Manufacturers of America. ''We're criticized on the Hill and in the press - put in the category of the tobacco industry, even though we save lives.''

The industry, Fingland said, has made great strides in the past three years - since a new ethics policy was implemented in 2001. Drawn up with the help of the American Medical Association and other medical specialty groups, it restricted the types of gifts given to doctors, for example, setting a $100 ceiling on each. Although pharmaceutical companies can still sponsor meetings, they no longer have free rein to treat doctors to five-star dinners or pick up their hotel tabs.

Despite the improvement, pharmaceutical executives are bracing for the worst.

''Moore's past work has been marked by negativity, so we can only assume it won't be a fair and balanced portrayal,'' said Rachel Bloom, executive director of corporate communications for the Wilmington, Del.-based AstraZeneca.

Rumors already are flying about Moore's moviemaking tactics. Moore, it is said, has hired actors to portray pharmaceutical salesmen who offer gifts to doctors who promote their products. There is also word that he has offered physicians $50,000 apiece to install secret cameras in their offices in an effort to document alleged corruption.

Tentatively titled ''Sicko,'' Moore's film will probably be released in the first half of 2006. No deal has yet been reached, but an announcement is expected after the new year.

Reached at his home in Michigan, the director declined to say whether he has hired actors to portray pharmaceutical salesmen and denied paying doctors to help him install secret cameras. (''I didn't need to. So many doctors have offered to help, for free, in an effort to expose the system.'') He does acknowledge hanging around hospitals, insurance companies and pharmaceutical companies, including two that have not issued internal alerts.

It's getting harder to find corporate executives, however, who are willing to sit down for interviews, Moore said.

Moore decided to make a film about health care because it's ''a hot-button issue with the average American - the domestic issue of the day,'' he said. ''Being screwed by your HMO and ill-served by pharmaceutical companies is the shared American experience. The system, inferior to that of much poorer nations, benefits the few at the expense of the many.''

Last summer, the Endeavor agency, which represents Moore, tested the Hollywood waters - sending out a six-page outline of ''Sicko'' to a host of independent producers, independent film companies and the major studios. The movie, according to the treatment, would end with Moore sailing to Cuba with ailing Americans to take advantage of that country's free health care. That, he says, was only a joke made on a late-night talk show.

The movie, Moore said, is only in its early stages ''and already people are freaky-deaky.''