And experts believe the true figure may be far higher as many shoppers are too ashamed to admit to the practice.
Nearly half of those who did confess said they were motivated by money because they couldn't afford to keep the clothes given the present economic climate. But 18 per cent said they did it because they enjoyed the 'buzz'.
The poll of 2,000 women in UK found the most common occasion to buy and then return an outfit was for a wedding. Others did it for christenings, black-tie events and Christmas parties.
The British Retail Consortium (BRC) said it was 'concerned' about the practice, and warned offenders would be caught, the Daily Mail reported.
Those most likely to do it were 18 to 24-year-olds, 16 per cent of whom admitted to returning worn clothes. This was followed by the 25 to 31-year-old category, on 14 per cent.
Hannah Priddey, 24, a masters student at Bristol University, said she bought a glamorous outfit, and returned it, once a fortnight for four years.
According to the survey, carried out by the UK-based OnePoll.Com, offenders tuck the labels inside clothes on a night out to conceal their strategy.
The next day they either hang them out to air or spray them with air freshener, then return them to the store, telling the shop assistant they didn't fit.
Shockingly, seven per cent of those surveyed said they had returned an outfit after being sick on it, while six per cent had spilled a drink on one and taken it back.
Eight per cent said they had left the item they returned in a crumpled heap on the floor all night, and nearly nine per cent said it smelt of smoke.
A spokesman for OnePoll.Com said: "It's understandable that people are tightening their belts and are spending more cautiously during this bleak economic time, but returning clothes after wearing them is quite dishonest and high risk".
Legally, shops are under no obligation to accept returns unless the goods are faulty or damaged. But in practice, many do as long as the customer has a receipt.
Sarah Cordey, of the BRC, said: "Most retailers go well beyond the legal minimum when it comes to returns policies, and the vast majority of customers use them honestly. Deliberately buying clothes to wear and then return is wrong and shop assistants are on the look out for signs of this".