Frank Herbert, 65, a science fiction writer whose galactic epic "Dune" sold more than 12 million copies worldwide after being rejected by 20 publishers, died Feb. 11 at the University of Wisconsin Hospital and Clinics. He had cancer.

"Dune" is another name for the fictional desert planet Arrakis that is the focus of galactic battle and intrigue because it is the source of a hallucinogen that prolongs life and is essential to space navigation. It was published in 1965 and was the first of six novels.

"Dune," eventually translated into 14 languages, became a cult favorite.

Nearly 20 years after "Dune" appeared, critic John Clute wrote in The Washington Post that Mr. Herbert's "adroit mix of religion, ecology, space opera, Arabs, giant worms, longevity drugs, politics, dynastic wars, extrasensory power and sex showed just how exhilarating the science fiction romance of conceptual breakthrough could be."

Mr. Herbert's latest "Dune" novel, "Chapterhouse: Dune," hit the best-seller list when it was published last year.

Although the movie version of "Dune" appeared to great expectations at Christmas 1984, it drew mostly bad reviews.

Before the success of "Dune," Mr. Herbert wrote suspense stories and articles and worked as a reporter on several newspapers, including the Oregon Statesman, the old Seattle Star and the Seattle Post-Intelligencer.

A native of Tacoma, Wash., Mr. Herbert studied psychology at the University of Washington. Jungian psychology, which preaches that universal symbols transcending language are common to all cultures, formed the foundation of "Dune" and the novel "White Plague."

Mr. Herbert, who lived on Mercer Island, Wash., is survived by his third wife, Theresa, and by two sons and one daughter.