In 2011-12, the NHS spent £1.5m on agency staff in the region, but that figure has steadily increased, rising to £5.07m for 2016-17.
Those figures were revealed by Shona Robison, the Scottish Government’s health secretary, during a debate at Holyrood.
They also show that NHS Scotland spent £171m on agency staff nationally.
A spokesperson for NHS Borders said: “There is a requirement to fill rotas and make sure staffing levels are adequate to ensure the safe delivery of care. When we have vacancies, this creates locum or agency cost.
“Unplanned activity also plays a big part when having to use agency staff. Opening extra in-patient beds due to an increased demand for our services can lead to a requirement for additional staff.
“During 2017, we successfully recruited a number of consultants including anaesthetists, psychiatrists, a general surgeon, a radiologist and physicians in gastroenterology and stroke medicine.
“All of these vacancies are specialties for which there is a shortage of qualified consultants, and the services were previously sustained by a reliance on agency doctors.
“In addition, last year until August, we experienced a high number of gaps in training-grade doctor rotations recruited through the Scottish medical training system.
“The allocation of training doctor numbers to NHS Borders was much more favourable in the August 2017 rotation and, as result, there is no further long-term reliance on agency doctors to maintain junior doctor rotas.
“We project costs of agency junior doctors will also have reduced significantly from August 2017.”
Ms Robison said: “Spend on nursing agency staff is very low, representing just 0.4% of the overall nursing budget. The majority of temporary shifts are filled from the NHS staff bank.
“There are also more than 35,000 nurses registered on the staff bank who are NHS staff on NHS contracts working at NHS rates of pay.”
South Scotland Labour list MSP Colin Smyth is unconvinced, though, saying: “There are now shortages of staff in almost every area and, as a result, NHS Borders has to spend over £5m a year on agency staff, a rise of just under 400%.
“The private agencies that provide the staff will be taking their cut and profiteering from the workforce crisis in our NHS.
“This is money which should be going to pay NHS staff that work all year round to provide healthcare for us.”