The Scottish Centre for Employment Research believes that image problems are a very real barrier to interview success.
Their conclusions are based on a survey of 500 high-street retailers in which they found that the vast majority had not hired staff because of the way they looked.
They also found that more than four-fifths of employers had an appearance policy, with set standards on personal hygiene, tidiness and dress.
The majority of firms also frowned upon visible tattoos, piercings and excessive make-up and jewellery.
"Our findings show that you could have the right qualifications and yet fail to be employed because you don't look 'right'," the Scotsman quoted Professor Chris Warhurst of Strathclyde University, eth study's lead researcher, as saying.
"Retail jobs are being targeted by Government as appropriate work for the long-term unemployed so it is essential that this group are not excluded from the labour market because they lack the appropriate presentation skills."
"Many potential employees might ask why they can't have streaks in their hair, a tattoo or a body piercing, things which are a personal expression. But many employers won't accept that and the likelihood is they won't be able to express themselves in that way in the workplace," he added.
The research showed that for most employers the appearance of potential employers was considered more important than their knowledge of the products they sold.