Thousands of ambulances sent out with single crew member
The Scottish Ambulance Service blamed staff absences for single manned crews.
Ambulances with just a single paramedic on board were dispatched to patients more than 10,000 times within the last four years, official figures show.
The Scottish Ambulance Service says single crew shifts only happen "due to short notice, unplanned staff absence where additional staffing cannot be arranged".
Last year, the sickness rate within the service was 7.6%, above its target of 5% and also higher than the national average of 1.9%.
During the last four years, lone paramedics were sent 10,029 times to patients.
The figures were obtained through a freedom of information request from the Scottish Conservatives.
Health secretary Shona Robison said: "The number of instances of single crewing remains low in comparison with the actual number of shifts across Scotland, taking into account the patterns of greatest demand for the service.
"The number of paramedics in Scotland between September 2007 and June 2017 increased by 13.9%, with staffing in the Scottish Ambulance Service up by 16.5% overall during that time, and despite increasing levels of demand our crews are saving the lives of more patients than ever before."
When previously serving as health secretary, Nicola Sturgeon said ambulances should only have one paramedic in exceptional circumstances.
Speaking in 2008, she said: "I have made it clear to the Scottish Ambulance Service that it must take action to eliminate rostered single-manning.
"The policy of the Scottish Government is clear - traditional accident and emergency ambulances should be double-crewed, with at least one member being a paramedic, unless in exceptional circumstances."
Scottish Conservative public health spokeswoman Annie Wells said: "Everyone accepts that in the emergency services there will always be times where rules have to be bent and people need to adapt to developing situations.
"But for single crews to be sent out on 10,000 occasions in four years-when the specific policy is not to do that-is unacceptable.
"The SNP government has to take responsibility for this. Nicola Sturgeon herself said she would end this practice nearly a decade ago but next to no progress has been made."