The Physicians' Desk Reference (PDR) is a widely used source of drug information by American physicians and patients, but as we shall discuss, it suffers from numerous shortcomings. The PDR is a collection of written and pictorial information that is provided and paid for by pharmaceutical manufacturers. The written material for a given drug is a compilation of data and recommendations that are identical to those in the drug's package insert. The wording and directives that are included in these package inserts (and thus in the PDR) represent information that the pharmaceutical companies are permitted to present following discussion and approval by the Food and Drug Administration (FDA), Rockville, Md. The PDR is thus a negotiated effort of commercial enterprises and governmental regulators.