The study of access to primary care in 2,509 surgeries found that being within 3km of a walk-in centre had no effect on waiting times for a GP appointment.
The researchers from the School of Health and Related Research at Sheffield University concluded in the BMJ that walk-in centres 'may extend and potentially duplicate' GP care.
The DoH welcomed the findings, saying that the centres 'attracted patients who would not have otherwise visited a GP'.
This was 'exactly our intention' because people fit in accessing healthcare around their daily lives, a spokesman said.
The study's lead researcher Dr Ravi Maheswaran, a public health doctor, said the conclusion 'leads into the government's choice agenda'.
The research team said they might see an association between shorter waiting times and a walk-in centre opening up within 3km of a GP's surgery.
But they showed that while 48-hour-access achievements improved from 67 per cent to 87 per cent of practices over the study's 21 months, proximity to a walk-in centre had no impact on this.
The lack of any effect led the researchers to conclude that walk-in centres should not be used to shorten waiting times to access primary care.