Bosses at Sainsbury's, which already has one surgery at a store in Manchester, says it has been contacted by doctors interested in opening practices to serve their local patients.
'Sainsbury's has around 200 stores that have the potential space and appropriate facilities to support a GP's surgery, in conjunction with a pharmacy already open on site,' according to a spokesman.
He said that the supermarket giant had not expressly approached any GPs or primary care trusts about opening surgeries, but inquiries had been made by family doctors looking to open practices.
The spokesman added that the scheme in Manchester's Heaton Park had provided over 1,500 consultations to patients since March 2008.
He said it was a huge success, with demand for appointments so strong that the service has now increased from three to four days a week.
Asda, which already runs two drop-in blood test clinics in stores in Birmingham and York, said it was also looking at the possibility of in-house GP surgeries.
Dr Laurence Buckman, chairman of the British Medical Association's GPs Committee (GPC), said: 'It seems these practices will be run by GPs as branch surgeries, so they have the potential to make primary care more accessible to patients. We will be interested to see what the uptake is.'