The original book, featuring a bearded man and his partner demonstrating the art of love in intimate if sketchy detail, sold millions of copies after its first publication in 1972.
But the new edition has been brought fully up to date -- for the first time by a female author, who, while praising the original author Dr. Alex Comfort, says there was much that needed changing.
"Back in '72 they didn't know about hormones, about pheromones, they didn't know about certain body parts and their importance, which we now know," said author and relationship psychologist Susan Quilliam.
"A lot of research has been done. But also the whole attitude to sex has changed," she told AFP.
The new book is aimed at the couple, rather than just the men, and includes many new entries including advice on internet and phone sex, sex shops and intercourse during pregnancy.
Quilliam noted that some tips from the original had to be removed, because they were illegal.
"One of them was having sex on horseback, the other was having sex on a moving motorcycle, although I do include guidelines on how to have sex on a stationary motorcycle," she said.
The publishers of the new 288-page edition, Mitchell Beazley, said it would "reflect the current attitude to sex and help bring the joy back into sexual relationships."
"'The Joy of Sex' is ingrained in our consciousness; this book is to sex books what Hoover is to vacuum cleaner," it said in a statement.
The updated volume, described as a "gourmet's guide to sex," is illustrated with photos as well as new drawings depicting a smorgasbord of sexual positions and techniques.
In place of the bearded 1970s male, the new edition features a short-haired, clean-shaven lover smiling repeatedly in a variety of clinches with an equally joyous brunette partner, in one shot tickling his buttocks with her tongue.
"The bearded man was an icon -- but he was a 70s icon. This is a book for the 21st century, so we needed a man (and a woman) for the noughties, not for the seventies," said Quilliam.
"So, though I may reminisce about the bearded man, I don't miss him!," she added.
Public reaction to the new edition has been positive -- it was published on Monday, and by Thursday had reached number 299 in the bestseller list of online retailer Amazon's British website.
Britons, not known for their openness about sex, were divided on the updated tome, according to an anonymous straw poll conducted by AFP on a London street.
"I don't think you need a manual," said one young man, sheepishly looking at his partner. Asked if he thought it all came naturally he agreed: "Yeah, it's finding out about each other."
Another woman, standing next to her husband, was more forthright. "We're married now so that's the end of that," she said.