Spain's top fashion designer is slumped in a chair, sucking on a Marlboro. She doesn't look like the glamorous vision her press clippings suggest, but Amaya Arzuaga can be forgiven. Having flown into London from Madrid, where she has been celebrating the end of Spanish Fashion Week, the 27-year-old looks in need of a rest. But that will have to wait. There is next Tuesday's fashion show to organise.

Arzuaga is half-way there already. Her spring/summer collection for men and women sits on rails in the spacious studio of her London agent, Palladio. There are similar rails in Paris, Milan, New York and Madrid. This is not unusual for a designer who despite her youth is extremely organised; she has 300 stockists world-wide, and an annual turnover of pounds 10m.

Arzuaga showed for the first time in London last March. The show made the front page in Spain, where she is designer of the year, but she seems uninterested by their adulation.

"Spain is not happening for fashion; it is very boring and very conservative, they all dress pijo," she says in her heavily accented English. Pijo is Spanish for preppy, or yuppy. She is lucky. Her father, Florentino, runs an exclusive vineyard which produces some of the finest red wine in Spain. His label, Arzuaga, guaranteed the young designer an instantly recognisable product; her mother, Maria Luisa, is also a knitwear designer and manufacturer.

The young Amaya grew up on a sprawling estate near Madrid. "It was not like Falcon Crest, you know," she insists when asked about her upbringing; and this is despite sharing the grounds of her family home with 300 wild deer. However, it is clear that she is now fairly shy of the high life. "I do not mix with fashion people, I live in the country and read a lot," she says. Ten years ago it was different. Miss Arzuaga was a wild child. She sang in a band called Impossible to be Worse, hung out with Almodovar's muse Rosie de Palma, and wore the most outrageous Gaultier she could find.

After attending the Madrid University of Fashion, Arzuaga designed her first knitwear collection, and sold it in Paris. She is known for clever and colourful knitwear designs that marry unusual fabric combinations, and for the latest in computer technology, but colour and texture is where she excels. "It is a preconception that I only do knits, " she says. In fact, though stores such as Whistles, Liberty and Browns Focus sell her jumpers, there is much more to Amaya Arzuaga clothes.

The collection that is being shown as part of London Fashion Week is her seventh. About one-third is knitwear; the rest is a confection of quirky, asymmetrical slip dresses with delicate embroidery. It also features candy-striped men's trousers and shorts. Elements of London style include hand-painted shirts and dresses, and lopsided vest tops with layers of stretch organza over textured prints. There is also a line of sunglasses and jewellery. What next? Well, if her clothes are anything to go by, her father's wine must be a very pleasant tipple. Waiter!

Portrait: Outumuro