The ratio of medical staff to beds is as high as one to 124 in some parts of the country, with recent graduates making up part of the team.
There is significant variation in how thinly doctors are spread between different district general hospitals, according to information provided by health boards to The Herald.
In some hospitals, such as Aberdeen Royal Infirmary and the new Forth Valley Royal, there are around 65 beds for every doctor on the night shift rota.
However, at the Royal Alexandra Hospital in Paisley the ratio is 124 beds per doctor, including three juniors in their first or second year on the wards.
Dr Neil Dewhurst, President of the Royal College of Physicians of Edinburgh, said: "It can be difficult to predict how many of these patients will require urgent treatment during the night, so it is essential to provide sufficient capacity within these rotas to cover both planned and unplanned care.
"The patient-to-doctor ratios reported by some NHS boards would suggest there may not be much capacity within some of these rotas to cover a high level of unplanned care, particularly if these rotas are further stretched by unfilled vacancies or staff absence."
From 8pm or 9pm medical cover is provided on most Scottish hospital wards by what is known as the Hospital at Night (HaN) team.
As part of The Herald's series investigating pressure on hospital services, we asked about the number and grade of staff manning the HaN rotas and the number of patients they were responsible for. This followed reports that junior doctors at St John's Hospital in West Lothian had complained about staff cover at weekends, describing conditions as "unsafe".
Inverclyde Royal, Crosshouse Hospital in Kilmarnock and the Victoria Hospital in Kirkcaldy all had more than 100 beds per doctor on their night system.
In total there were six hospitals with more than 100 beds per doctor, including scenarios where the doctors were covering more than one facility, such as Gartnavel and Drumchapel hospitals in Glasgow. In addition, the Western General in Edinburgh had more than 100 beds per doctor on Friday, Saturday and Sunday nights.
HaN teams have to respond to the needs of patients on medical and surgical wards and may also provide cover for high-dependency units and acute receiving units.
Dr Dewhurst said: "As NHS boards can record data in different ways, this data would benefit from verification. However, the data clearly suggests variation in cover for out-of-hours medical care in hospitals throughout Scotland.
"The limited research that is available would suggest that patient to doctor ratios have not changed much over the last decade and that small numbers of doctors continue to be responsible for large numbers of patients at night."
On-call consultants are available at home for all the hospitals and additional doctors man other hospital departments, such as A&E, at night.
At some centres, such as Crosshouse, a trainee anaesthetist is on site. Other staff, including highly qualified nurses, also play key roles on most nightshift teams. Some health boards say these nurses have the same expertise as medical graduates, known as FY1 and FY2s, who are doing their first two years on the wards.
Dr Dewhurst said little evidence had been collected about safe staffing levels at night.
A snapshot survey of doctors in England and Wales in 2010 found doctors were responsible for an average of 61 patients at night. However, there was a wide variation of up to one doctor for 400 patients.
Heather Knox, director of acute services for NHS Fife, said: "Our Hospital at Night team model reflects seven years of local development based on tried-and-tested models developed by the Department of Health (England) and nationally supported Scottish developments. This collective direction and our current experience has demonstrated that the Advanced Nurse Practitioners are functioning beyond FY1 level, closer to FY2 level.
"That would reframe the calculation to seven Junior medical staff or equivalent for 504 in patient beds, a ratio of 1:70."
NHS Greater Glasgow and Clyde, which runs the Royal Alexandra and Inverclyde Royal, said: "Given these are Hospital at Night services there is significantly less activity than during the day when patients are awake.
"The composition of each HaN team is not determined solely by the number of beds on a hospital site, but it also takes account of the physical layout of the hospital, and the range and complexity of clinical services provided in each hospital. There is close and continual monitoring of each of the HaN teams to ensure that on each individual hospital site the HaN team provides safe and appropriate care."