Dr Macbeth (66) said he had a loyal group of patients it had been a privilege to serve.
He would occasionally work as locum in his retirement, which began last week.
For one family, he had looked after five generations, which was very special.
Dr Macbeth established the Musselburgh Medical Centre in 1983. His first years as a GP were spent a few doors away from the current practice, with the late Dr Jock Hazeldine.
He is philosophical about the changes he has seen over nearly four decades.
He was a supporter of ''Dr Google'', and did not have a problem with patients researching their symptoms online. The internet was handy for doctors too, reducing their reliance on textbooks. Patients no longer put doctors on a pedestal, which was a good thing. It meant they took more interest in their own care.
Home calls had greatly reduced, although, contrary to what many thought, they were still made.
He had been involved with developing Dunedin's after-hours medical service, which had greatly improved GPs' family lives.
Some trends did concern him, he said. Patients worried less about seeing the same doctor for each appointment, and this reduced continuity of care.
He had also witnessed the declining availability of surgical services, which meant GPs increasingly had to manage patients needing surgery. This was frustrating when everything possible had been done for the patient in general practice.
He thanked his wife, Joy, whose support had allowed him to work the necessary long hours. Three of their four children have settled in Dunedin, and he said he was looking forward to spending more time with his nine (soon to be 10) Dunedin-based grandchildren.
He also thanked his staff, who had contributed greatly to the success of the practice.
Dr Macbeth was touched by the farewells from patients in recent weeks, who had given gifts and cards, and some had even taken him out to lunch.
A sense of humour and his Christian faith had been central to his work, he said.
Dr Macbeth's last day was Thursday.
