Healthcare Improvement Scotland (HIS) inspectors noted the incorrect forms during an inspection of care for older people at the Southern General Hospital in Glasgow.
It has asked NHS Greater Glasgow and Clyde (NHSGGC) to make improvements in 16 areas following the report, which also highlighted two areas of strength.
The inspectors examined "do not attempt cardiopulmonary resuscitation" (DNACPR) documentation, which relates to the emergency treatment given when a patient's heart stops or they stop breathing.
Six of the nine forms which they reviewed had been completed incorrectly.
The inspectors were also "concerned" about patient flow and capacity at the Southern General, where they found that patients were moved between wards to meet the needs of the service rather than the patient's clinical needs.
They found that a patient with dementia and increased confusion had several ward moves, contrary to the health board's policy.
They also noted that 48 patients were listed as delayed discharge, with some waiting up to 54 days to be allocated a social worker so that an assessment of needs could be carried out.
The report said: "This is detrimental to the patients as it can lead to issues with cognitive impairment, increased risk of infection and impact on functional ability.
"Patients should not be kept in hospital longer than they should be."
Concerns were also raised over the prevention and management of pressure ulcers.
According to national guidance, a risk assessment should be carried out within six hours of admission, but this was not done in 21 out of 29 cases.
Two patients did not have their risk assessment carried out until 13 days after they were admitted.
Nutritional care was another area of concern. In eight out of 29 cases reviewed, patients did not have a malnutrition risk assessment carried out within 24 hours of admission.
One patient was only screened twice in a six-week period, despite being identified as at risk of malnutrition.
Jacqui Macrae, head of quality of care at 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.
"We did, however, observe friendly and polite interactions between staff and patients, with most speaking positively about the quality of care received.
"We saw the use of calm and contrasting colours in the Langlands building and found a specifically-designed garden for patients with dementia or cognitive impairment within the medicine for the elderly ward."
The unannounced inspection was carried out from February 18 to 20.
HIS said that the health board must improve the documentation in the clinical areas to ensure that appropriate care is given to patients and improve working practices with social work departments to make discharge planning more effective.
Rory Farrelly, NHSGGC's acute director of nursing, said: "Clearly we need to reinforce some of our policies with staff and provide additional training where required.
"It remains our policy not to move patients with cognitive impairment unless under exceptional circumstances and the instance referred to in the HIS report was one of these occasions.
"It remains one of our highest priorities to prevent this happening to older people and to ensure that the patient's interests are best served while in our care."
He added: "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.
"If one of our hospitals is experiencing such a surge we divert GP emergencies to the nearest neighbouring hospital, thus ensuring that our hospitals remain open at all times."
The health board has produced an action plan to address the issues raised by the inspectors.