Records for some people who had been identified as "not for resuscitation" had not been completed properly when inspectors visited the Gartnavel General Hospital in Glasgow.
Inspectors identified 15 areas for improvement relating to nutrition, resuscitation procedures and dementia screening.
The report by Healthcare Improvement Scotland found that only one out of six Do Not Attempt Cardiopulmonary Resuscitation (DNACR) forms had been completed correctly by staff.
Three had been signed by junior doctors with no countersignature from the consultant responsible for care and on one form there was no evidence the patient had the capacity to make the decision.
Inspectors found mealtimes for elderly patients were poorly co-ordinated and patients were not prepared before their meal arrived.
A patient who was screened as "high risk" for malnutrition three days after admission was not checked again until three weeks later. Patients are required to be screened within 24 hours of admission and then weekly if identified as "high risk".
Inspectors said wards were not "dementia friendly" and screening for cognitive impairment was not routinely carried out in patients over 65 years when they were admitted as required.
There was "limited evidence" of effective discharge planning for patients, which can lead to patients being kept in hospital longer than required.
The elderly care inspection, by Healthcare Improvement Scotland, also found some patients are often moved from the Western Infirmary to Gartnavel in the late evening. The health board said an internal transfer system had been introduced to prevent late transfers.
NHS Greater Glasgow and Clyde also said it had put together an action plan to address the other areas for improvement.
However, inspectors saw good examples of caring and caring and friendly interactions between staff and patients.
Patient care was carried out in a way that maintained patient dignity and respect.
Of the 75 patients who completed a questionnaire, 92% said the quality of care they received was good.
Rory Farrelly, NHS Greater Glasgow and Clyde's Acute Director of Nursing said: "We were pleased the inspectors noted interaction between staff and patients was warm and caring, and that the majority of patients were positive about their stay.
"However, we recognise there are still areas we need to address and an improvement plan has been developed."