WASHINGTON, Sept. 6 — Makers of drugs and medical devices would be required to report publicly nearly all payments and gifts to doctors under legislation introduced Thursday in the Senate.

“Right now, the public has no way to know whether a doctor’s been given money that might affect prescribing habits,” said Senator Charles E. Grassley of Iowa, the ranking Republican on the Senate Finance Committee and one of the bill’s authors.

Senator Herb Kohl, Democrat of Wisconsin, said drug and medical device makers had long defended their payments and gifts to doctors as appropriate.

“If that is the case, full disclosure will only serve to prove them right,” Mr. Kohl said.

Ken Johnson, senior vice president at the Pharmaceutical Research and Manufacturers of America, said, “A new law is not necessary when pharmaceutical marketing is already heavily regulated by the Food and Drug Administration.”