NHS Grampian is facing compensation claims of at least £24.4m after nearly 100 allegations of medical failings were lodged by patients.
Allegations of failures to diagnose illness and medical negligence were the most common reasons for suing the board.
Patients are also suing for hospital acquired infections, botched plastic surgery and infected wounds.
A spokeswoman for NHS Grampian stressed that a number of the claims were historic with some taking years to resolve.
She said: “Claims such as these can take many months or even years to resolve. They may relate to procedures or incidents which took place months or years before a claim was lodged.
“It is also worth remembering that not all claims for compensation will find in favour of the pursuer.
“We have more than a million patient contacts each year and the vast majority of patients are very satisfied with their care and treatment.
“These claims represent a very small proportion of the number of patient contacts we have and is no reflection on NHS Grampian’s standards.”
Any compensation paid would not come from NHS Grampian funds but through its insurance scheme, the spokeswoman added.
More than 1,500 legal actions were being taken up against health boards across Scotland.
Separate figures released last year showed that NHS Grampian paid out more than £1million in 2013 after 25 successful claims were settled.
Margaret Donald, of pressure group the Patient Action Co-ordination Team (PACT), said the latest Grampian figures came as “no surprise”.
She said: “We’ve suspected for some time that many large compensation claims have been lodged, but information has been difficult to access.
“We’re greatly relieved that this is now in the public domain and have full confidence in the new management who will have our ongoing support in the formidable task ahead.”
Aberdeen Central SNP MSP Kevin Stewart said it was a “last resort” for patients to sue the board.
He said: “It’s always a concern when a patient has to resort to having to claim for compensation but we must remember that the vast majority of people who use NHS Grampian services continue to rate them very highly.”