Paul Krassner was editor and frequent contributor to the Freethought magazine The Realist, which, first published in 1958, is a very early example of the countercultural press in the United States. Although The Realist is regarded as an underground publication by some, it was a nationally distributed newsstand publication as early as 1959.

The Realist was published on a fairly regular schedule during the 1960s and then on an irregular schedule after the early 1970s. It was revived as a much smaller newsletter during the mid-1980s when material from the magazine was collected in The Best of the Realist: The 60's Most Outrageously Irreverent Magazine (Running Press, 1985). The final issue of The Realist was #146 (Spring, 2001).

Krassner was a child violin prodigy (and was the youngest person ever to play Carnegie Hall, in 1939 at age six), but his career took a different turn in the 1950s when he became an important figure in many aspects of politically-edged humor and satire in the US. He was a close protege of the controversial comedian Lenny Bruce (he edited Bruce's autobiography); he worked on early issues of Mad; he was a founder of the Youth International Party in 1967, famous for prankster activism. He is known in intellectual property circles for having printed The Realist's controversial 1966 poster, "The Disneyland Memorial Orgy", illustrated by Wally Wood in black-and-white line art. Krassner recently made Wood's poster available in a digital color version.

Krassner remains a prolific writer and stand-up comedian. Currently, he is a columnist for the New York Press, Disinfotainment Today and AVN Online. He is a contributing blogger at The Huffington Post.