The ratio of doctors to beds is running at one to more than 100 at some hospitals during the night, according to health boards.
Figures show variation with the number of doctors on rota to care for patients during the night among NHS boards and hospitals.
Medical cover is provided on most hospital wards by what is known as the Hospital at Night (Han) team which includes junior doctors in their first year out of medical school, as well as more experienced staff.
In some hospitals the doctor-to-bed ratio is one to 65 but at others it is one to more than 100 beds.
Royal Alexandra Hospital in Paisley has 623 beds covered by an Han team of just five doctors, around one doctor to 125 beds. This includes three junior doctors in their first or second year out of medical school.
Gartnaval General and Drumchapel Hospital in Glasgow have a ratio of one doctor to 116 beds, which is matched by Western General in Edinburgh which has the same ratio covering Han beds at weekends.
Inverclyde Royal Hospital in Greenock has one doctor to 105 beds, while Victoria Hospital in Kirkcaldy has a ratio of one doctor to 103 beds.
Dr Neil Dewhurst, president of the Royal College of Physicians of Edinburgh, 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.”
Han teams are responsible for covering all medical wards.