The "Casualty Watch" looked at the accident and emergency departments of 52 hospitals in London and the surrounding counties.
The snapshot survey, carried out by local community health councils, found 18 patients who had been waiting on trolleys for more than 10 hours.
The worst case, at St Peter's Hospital in Chertsey, Surrey, involved an 82-year-old waiting for more than 25 hours on a trolley, and a 71-year-old who had been waiting for almost 24 hours at Whipps Cross Hospital in east London.
January is a month in which hospital accident and emergency departments are more likely to struggle, as poor weather leads to a surge in respiratory problems, falls and complications of flu.
This year has so far been relatively mild for flu, with the number of cases still holding at a very low level across the UK.
Scots speed
And the length of waits discovered by the survey compare unfavourably with a similar survey carried out in Scotland, which found maximum waits of approximately four and a half hours.
A statement from the Department of Health conceded that some people were still having to wait too long for a bed.
The spokesman said that the government's investment plans would ease the situation - with the result that by 2004, no-one should have to wait longer than four hours in accident and emergency from their time of arrival to either admission, transfer or discharge.
And the department suggested that many of those suffering the longest waits in the survey may have been found on A&E "observation" wards, a halfway house between the casualty department and a general ward.
"Most A&E departments have these and we think many of these patients may actually have been looked after in them. But the casualty watch survey doesn't seem to take account of this."
Community health councils, which carried out the survey, are due to be abolished by the government and replaced with hospital-based "advocates".
Malcolm Alexander, chief officer of Southwark Community Health Council, who drew up the report, said: "These figures are disgusting.
Shadow health secretary Liam Fox said: "I was disturbed but not surprised by these figures, because we've seen these figures remain fairly constant for some time.
"We are seeing across the country very long trolley waits and it is mostly people waiting for admission, sometimes elderly patients and sometimes for a very long time."