The head of NHS Scotland has told MSPs it is "close to impossible" to recruit new GPs in some parts of the country.
But Paul Gray, chief executive of NHS Scotland, rejected claims of a "failure" in workforce planning in the health service.
The Royal College of GPs in Scotland has predicted a shortfall of 856 GPs in Scotland by 2021 and a recent Audit Scotland report raised concerns over a lack of staff.
Mr Gray was appearing before MSPs on Holyrood's Public Audit committee where Tory MSP Liam Kerr said that in his North East constituency there were "significant workforce challenges" in the NHS.
"I cannot help but conclude that we're sitting with a depleted workforce because nobody has apparently planned for it in the past," Mr Kerr said.
Mr Gray said he was "not complacent" about the issues.
"In some areas in general practice it's very difficult to recruit - close to impossible.
"I accept that as a fact, I'm not pretending it doesn't exist."
Highland region also has particular problems with radiology staffing, he added.
Mr Gray was told that the heads of Scotland's regional NHS boards claimed last week there had been a collective failure across the health service to plan for the future.
But Mr Gray said: "Nobody has failed to plan."
"We are where where we are because of changes in context, changes in demand, changes in the way that we do things.
"We've reached the conclusion, I think rightly, ministers have reached the conclusion that a national workforce plan was now necessary. That is what we are producing. If every time we produce something new, we describe the past as a failure, it's going to make it very hard to produce anything new."
Patient satisfaction with the NHS are at 90%, the civil servant added.
"That is evidence of success, that is not evidence of failure," he said.