Milton Keynes hospital has spent almost £2 million on hiring nursing staff from agencies over the past two years.
The figures have been revealed this month following a Freedom of Information request.
Around £1.8 million has been spent on general nursing staff during the 23 months between January 2011 and December 2012, while the remainder has been spent on critical care nurses.
The hospital uses the agencies, which all charge a fee, when employed staff go off sick or on holiday.
Joe Harrison, chief executive of Milton Keynes Hospital NHS Foundation Trust said: “For the financial year of 2011 2012, the cost of agency staff including nurses and doctors was 4.2 per cent of our total £110.7 million spend on staff.
“Milton Keynes Hospital is committed to ensuring each patient receives high quality, safe care every day.
“This means the Trust uses agency nursing staff to cover absence, for example annual leave or sickness, so the hospital has the right set of nursing skills on each ward and department.
“The hospital continues to invest in nursing staff to cope with fluctuations of demand on services.”