The NHS could be facing a "financial timebomb" with more than 10,000 equal pay claims not yet resolved, Labour said.
There are still 10,035 claims outstanding against health boards across the country, Health Secretary Alex Neil said.
The total was revealed in an answer to a question from Labour health spokeswoman Jackie Baillie. She is now demanding an assurance from the Scottish Government that patient care will not suffer as a result of payouts.
Tories have also raised concerns about the "massive" number of equal pay claims still to be resolved. Conservative MSP Margaret Mitchell said they leave health boards with a bill for millions of pounds "hanging over them".
NHS Greater Glasgow and Clyde has the largest number of unresolved claims at 4,140, followed by NHS Ayrshire and Arran at 1,704 and NHS Lothian at 1,632. Both NHS Orkney and the Scottish Ambulance Service have just one outstanding claim each.
Labour and the Tories are demanding action to ensure the claims are dealt with. Ms Mitchell, the Conservatives' local government spokeswoman, said: "Where there is a case to be resolved, it should be done so promptly and efficiently."
Ms Baillie said: "It is a disgrace that in 21st century Scotland, women still are having to fight to achieve equal pay in the public sector. What is also more worrying is the financial timebomb that these claims pose for the NHS and the taxpayer.
"We have no idea how many millions these will cost us and I urge health boards to move swiftly to settle these to provide certainty and equality for all staff."
The Tories said the NHS has already spent £586,475 on equal pay claims, averaging £4,159 per case. If applied to the outstanding claims, this would mean a potential bill of £41 million.
Ian Reid, chair of the NHS Scotland Equal Pay Reference Group, said: "Whilst it is correct that a large number of equal pay claims are outstanding, they are unlikely to succeed and to suggest that they all require to be settled is misleading." He added: "It is further incorrect to suggest that there has been a delay by NHS Scotland in dealing with any stage of the tribunal process."