Some of the 48 patients who were listed as "delayed discharged" at the Southern General Hospital, Glasgow had waited up to 54 days to be allocated a social worker to allow assessment of needs, inspectors said.
Officials from Healthcare Improvement Scotland said they were "very concerned" about the practice, which they said was both "detrimental" to patients and had a direct impact on the number of people who can be admitted to wards.
Patients with dementia were also being moved between wards and hospitals because of a lack of space, although NHS Greater Glasgow and Clyde's own policy says people with cognitive problems are not shuffled around because they are running out of beds. During a three-day surprise visit to the Southern General, the inspectors witnessed one dementia sufferer being transferred from a different hospital in the middle of the night to make space.
The team also discovered one qualified nurse, backed by two support workers, was being left in charge of 25 patients at night for "considerable periods" because the other nurse was tied up admitting patients who could not be accommodated elsewhere.
Jacqui Macrae, head of quality of care for HIS, said: "During this inspection, we were particularly concerned about patient flow and capacity within the hospital. On the majority of wards inspected we found no evidence of care plans being used to inform and evaluate the care given to patients."
The inspection report, published by HIS yesterday, noted two areas of strength at the hospital and listed 16 areas for improvement. The staff were described as friendly and polite, and the report praises the garden area designed for patients using the medicine for the elderly unit.
But in addition to the issue of overcrowding and delayed discharges, issues were also found with the assessments patients require when they are admitted to hospital.
Jim Pearson, deputy director of policy at Alzheimer Scotland, said: "A number of problems highlighted in this report are unacceptable, particularly those relating to the inappropriate moving of patients between wards. Sadly, they are not uncommon."
Rory Farrelly, NHS Greater Glasgow and Clyde's acute director of nursing, said: "We are pleased to note that the inspection team observed friendly and polite interactions between staff and patients, with the most of the patients interviewed speaking positively about the quality of care received.
"However we are sorry that in a number of areas we are still falling short of the standards expected in all our hospitals.
"Clearly we need to reinforce some of our policies with staff and provide additional training where required."
He said the policy was not to move patients with cognitive impairment unless circumstances were exceptional, and added: "We take note of the specific comments in the HEI report about capacity at the Southern.
"It must be understood that we use our inpatient acute beds flexibly across all our hospital sites to give us sufficient capacity to cope with patient demands including when there is a surge at any one particular hospital."
The opening of the new Southern General hospital next year will increase numbers of hospital beds in the city. The Southern, Western and Victoria hospitals, including Mansionhouse, currently have 1620 beds. The new Southern General will have 1631 beds.