The Health Sciences Association of Saskatchewan did the survey and released the results Friday.
The union represents 200 hospital pharmacists across the province.
Union president Karen Wasylenko is calling on health regions to publicly disclose staffing levels and job vacancies, adding that it is public money and the public should know.
The pharmacists said in the survey that understaffing has led to alarming pharmacist to patient ratios.
The survey says that most hospital in North America have one pharmacist for every 20 patients, but in Saskatchewan, it is one to 70 to 100 on most days.
The union says there is no emergency room pharmacist at the General Hospital in Regina.