Figures show that 2,576 non-emergency operations (9 per cent) were cancelled in August alone with nearly one fifth of these (17 per cent) scrapped due to lack of capacity - such as shortages of beds and staff - at hospital.
At NHS Borders, more than one in 10 (12 per cent) of its planned operations were cancelled during the month.
Of these, just over 60% were down to lack of bed space or other non-clinical issues- the worst rate in Scotland.
A spokeswoman for NHS Borders said the breakdown of a ventilation system in one of the operating theatres, which was out of use for four days, plus a high number of emergency admissions requiring surgery was behind the figures.
Work was being carried out to improve performance, she said,
NHS Highland, which has faced severe budgeting issues with a £3.4m overspend in just six months this year, had 212 planned non-emergency procedures cancelled during August (15 per cent).
Of those cancelled, just under a third (30%) had to be rescheduled due to capacity issues.
In Grampian, which has suffered long-documented staffing issues, 269 non-emergency operations were cancelled during the month, around 8.5 per cent of the total.
Of these, around a fifth (22 per cent) were rescheduled due to lack of hospital capacity, with 60 patients told their operations would not go ahead as planned for this reason.
In addition, 125 patients decided to cancel their procedure - the second highest figure in Scotland.
At NHS Lothian, 65 patients were rescheduled in August because the hospital was unable to accommodate them.
The board also had the highest number of patients cancelling their treatments, with 261 people choosing not to go ahead as planned (5 per cent).
In total, 1,058 operations in Scotland were cancelled last month due to patient choice.
Capacity issues generally hit hospitals the hardest in the winter due to high numbers of people treated on wards, particularly the elderly.
Bed blocking - when patients are unable to leave hospital because the right level of social care is not in place for their return home- is now a major issue in Scotland.
Health Secretary Shona Robison said she has made clear to boards that operations for patients with the highest needs must not be cancelled.
She said: ““A very small number of operations planned in Scotland are cancelled for non-clinical reasons. The latest figures on this show that in August only 1.6 per cent of all planned procedures were cancelled for this reason.
“However, the decision for a board to postpone an elective procedure is never taken lightly. Health boards work to ensure disruption to patients is always kept to an absolute minimum, and any postponed procedures will be rescheduled at the earliest opportunity.
“We are working with health boards to makes sure we manage capacity and planning in order to keep cancellations to a minimum. I have also been clear with boards that procedures for patients with the highest clinical need should not be cancelled.”