Ambulances waited outside hospitals for the equivalent of more than 41 years in 2024, figures show.
The data, released by the Scottish Ambulance Service after a freedom of information request, reveals it took ambulances a total of 361,753 hours to unload and depart from hospitals last year.
The figure represents a more than 10% increase from 2022 when the total turnaround time was 322,828 hours.
NHS Grampian recorded the single highest turnaround time in 2024, with an ambulance waiting at a hospital in the area for 16 hours and 42 minutes.
This figure was 44,741 hours in NHS Lothian and 26,346 hours in NHS Fife.
Between 2022 and 2024, it has taken ambulances a total of 1,012,848 hours to turn around, the equivalent of more than 115 years, the data shows.
The Scottish Liberal Democrats, who obtained the figures, said the delays mean patients are not getting the care they need.
MP Christine Jardine said the Scottish Government must fix problems at "both the front door and the back door" of the NHS.
Scottish Liberal Democrat MP Christine Jardine described the figures as 'devastating´ (UK Parliament/Jessica Taylor/PA)
She said: "These are devastating delays. They reflect all those people who have waited in agony for an ambulance to arrive, frightened that one may never come.
"Under the SNP, despite the best efforts of staff, ambulances are waiting longer and longer outside of hospitals because staff are struggling to find the space to receive new patients.
"It's preventing people from getting the care and treatment they desperately need.
"The Scottish Government must finally get serious about tackling the problems at both the front door and the back door of the NHS.
"That's why Scottish Liberal Democrats are so focused on repairing the crisis in social care, starting with a new UK-wide minimum wage for care workers that is £2 higher.
"This will give more people the care they need at home or in the community, freeing up space and capacity in hospitals and getting ambulances on their way to the next callout as swiftly as possible."
Health Secretary Neil Gray said: "Patient safety and the welfare of NHS staff are our top priorities.
"I apologise to any patients who have experienced delays and their families. We recognise the significant pressures which healthcare staff face.
"While our A&E performance is the best in the UK, we continue to work closely with Health Boards and the Scottish Ambulance Service to support the safe handover of patients upon arrival at hospital.
"Our £200 million of targeted investment will improve patient flow, enhance capacity and tackle delayed discharge."
A spokesperson for the Scottish Ambulance Service said: "We continue to experience significant pressure on our services due to lengthy hospital turnaround times at a number of hospital sites across Scotland.
"These waits prevent our crews from getting back out on the road to treat other patients, and we are working closely with health boards supporting their efforts to improve the situation."