New figures show that the total number of nursing and midwifery vacancies has risen from 615 in 2011 to 2,411 in September this year.
Over the same period the number of consultant vacancies has risen from 112 to 345, with the proportion vacant for more than six months rising from 0.9 per cent to 2.6 per cent.
Alison Johnstone, Scottish Green MSP for Lothian, said:
"Although the number of people employed in the NHS overall has slowly risen in recent years, recruitment and retention of key frontline staff has not kept pace. The near-trebling in the rate of consultant vacancies lasting more than six months does not give confidence that Scottish ministers are on top of the situation.
"We know that our health service is under increasing demand and we know that recruiting qualified staff is a challenge due to the length and cost of training. Existing staff are working hard to cover gaps and we're spending millions on agency workers. This situation isn't fair on staff and isn't sustainable for NHS finances.
"We must increase our efforts to retain skilled health workers who train in Scotland as at the moment many find it more attractive to work overseas. And we must challenge the UK's restrictive approach to immigration which prevents talented workers from abroad filling roles here."