Madonsela was visiting the Northern Cape as part of her national stakeholder dialogue programme on Tuesday.
"The state of the hospital is quite disappointing," she said in a statement.
However, she commended the personnel as "incredible people" who were working in the conditions found.
The 45-bed hospital only has one doctor after two resigned two months ago. The hospital has a 95% utilisation figure.
The single doctor, who was almost never off duty, has seven professional nurses and 11 enrolled nurses, who work on eight-hourly shifts.
One nurse is on duty at night.
Lack of quarters
?Health officials told Madonsela plans were in place to appoint two more permanent and a few sessional doctors but they were struggling to attract health care professionals.
One of the reasons was lack of staff quarters. The doctor was staying in a converted garage.
The province was also waiting for the return of about 50 doctors, who went to study in Cuba.
Some would be deployed to the area.
Madonsela said her office would help provincial authorities to work out plans to address the Postmasburg Hospital problems and oversee the implementation thereof.
The public protector also met with residents of the Tsantsabane Municipality on health, poverty and general service delivery issues.
Residents told her about problems with mine bosses and land, friction with land reform groups, problems with the municipality in regard to tenders and staff recruitment's and other service related issues.
Madonsela is expected to be in the Kimberley area on Wednesday and Thursday. – Sapa