Why is the Hayward offering us another major Warhol exhibition when only last year we were treated to a huge Warhol show at the National Gallery of Scotland? In 2002 Tate Modern put on a definitive Warhol retrospective and before that there was the Hayward's own classic retrospective in 1989. His name is a synonym for contemporary art. Yet the curator Eva Meyer-Hermann is adamant that this exhibition, already shown in Amsterdam and Stockholm, will be different. “Everyone knows the Monroe screen prints and the soup cans,” she says. “This show will present a selection of other aspects of the artist which together will strip him bare.”

Two thirds of the exhibition is devoted to Warhol's film and video work, the rest focuses on what should really be called Warhol's Miscellaneous Extras. Warhol was obsessive about collecting and on display here are a few of the 600 time capsules that he made in the 1960s, self-consciously establishing a repository of the essential elements of the cultural Zeitgeist that swirled around him. These took the form of cardboard boxes full of old postcards, Christmas cards, telephone notes, photographs, cinema tickets and the odd T-shirt. There are covers of his magazine Interview. There are books, contact sheets, photomat strips and wonderful expanses of his wallpaper: Chairman Mao, cows and Warhol's face repeated hundreds of times in bright colours.

But the meat of the show is in the videos and films. The videos start with the seldom seen Factory Diaries, the obsessively self-referential films that Warhol and friends made during the 1970s. These unedited films and screen tests are part of Warhol's compulsive reproduction of what was going on around him. They include long unedifying footage of Warhol reading the paper and half-heartedly discussing, at some length, with his friend Geri Miller, what might have happened to her ex-boyfriend's shirt, and, more divertingly, the artist Neke Carson working with intense seriousness painting a portrait of Warhol using a brush apparently clenched between his buttocks.

The visitor then steps into a highly designed Stars and Stripes “TV-scape” to watch all 42 episodes of Andy Warhol's TV, which were broadcast on television regularly from the late 1970s until his death in 1987. All his life Warhol longed to be close to the stars and his television shows allowed him and his chosen interviewees the chance to be famous. The footage tended towards the subjects of fashion, beauty and fame, and covered the glamorous and the trivial alike.

The largest section of the exhibition is the “Filmscape”, a room with 19 full-size screens showing a selection of Warhol's long feature films on loops. The viewer is greeted with the sight of Mario Montez in drag eating a banana, hinting bluntly at the metaphoric possibilities. There follows, in carefully designed viewing booths, a series of feature length films including Chelsea Girls, Henry Geldzahler (a 99-minute film of the former curator of contemporary art at the Metropolitan Museum of Art, staring at the camera and smoking a cigar) and Sleep, the five-hour film of his naked boyfriend sleeping. There are 19 films in all and you can buy a special pass to come back as many times as you wish to watch them at full length.

This show does offer a fresh focus on Warhol, but the footage is long and often dull or obscure. It is the artist's least accessible side. Twenty-one years after his death, Warhol still commands remarkably greedy levels of attention. On Thursday, three of the “superstars” of Warhol's Factory world, Holly Woodlawn, Bibbe Hansen and Mary Woronov, will be talking at the Purcell Room about their memories of Warhol and the Factory. There is clearly still an appetite for all this.

Andy Warhol, Other Voices Other Rooms is at the Hayward Gallery (www.hayward.org.uk), from today

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