At least 21 new supermarkets from the 'big four' chains were given the go-ahead in and around Bristol in the past two years, BBC research has found.
That is almost half of the 44 Asda, Morrisons, Sainsbury's and Tesco stores given permission in the West.
Only one of the stores was a new-build and needed full planning permission.
One of the most controversial stores was a Tesco Express in Stokes Croft which campaigners are still trying to prevent from opening.
The UK-wide research aimed to discover the number of new supermarkets given approval between 1 November 2008 and 1 November 2010.
It found that at least 577 stores - 392 of them Tesco - were approved across the UK during that period.
Bath and North East Somerset Council has not yet responded to the research so the number of new supermarkets in the Bristol area may be higher. Also, an application for a new Sainsbury's store in Portishead is still pending.
The research showed the overwhelming trend in the West was supermarkets moving away from the large out-of-town sites and buying high street shops and retail units.
In Stokes Croft, campaigners have been trying to stop Tesco opening in a former comedy club for more than a year and have stopped it being granted a licence to sell alcohol.
It did not need to make a planning application for the store because the building was already classed as being for retail use - only advertising consent was needed for a lit sign.
The sign was given the go-ahead by city councillors earlier this month despite demonstrations by some who feared the road would lose its "character".
The No Tesco In Stokes Croft group has said it will take legal action against the decision.
Claire Milner, from the group, said: "Stokes Croft is renowned for its community spirit, its cultural distinctiveness and its independent traders - the antithesis of supermarkets.
"We wish more communities could enjoy the quality of life that comes from resisting the lure of consumerism. Tesco represents everything our community is rejecting.
'Embedded in community'
"We need to protect our independent shops as they hold the keys to ensuring everyone can afford to eat healthily in the future.
"If supermarkets are allowed to continue to dominate our food system only the rich will be able to afford a nourishing diet - the rest of us will simply be priced out.
"Admittedly some of our local shops have a long way to go in terms of representing a positive alternative however, unlike supermarkets who answer only to their shareholders, our local shops are embedded in our community and can and will respond to our needs."
She said the group was seeking a judicial review into Bristol City Council's decision, and would also be launching a campaign to highlight alternatives to supermarkets.
A spokesman for Tesco said: "The Stokes Croft area of Bristol has many empty shop units, we are pleased to be able to put one into good use, creating around 20 new jobs.
"Bristol Council has now approved our applications and we look forward to opening the store for customers. This is a small convenience store offering great value fresh food and household basics."
He added: "Most of our new store applications are not for large supermarkets but for small, local convenience stores, the likes of which millions of customers have relied on to get food in the bad weather."