An inspection was carried out last month at Kingsmead home in Kingswells.
The Care Inspectorate said some residents, who were unable to use cutlery, were trying to eat soft food with their hands, leaving their clothing stained.
Service at the home was graded as "weak".
A persistent unpleasant odour was noted throughout the home, and equipment, including commode chairs and mattresses were found to be in need of a deep clean.
It was claimed some residents were unkempt, with ungroomed hair and dirty nails.
Few people were being given baths or showers regularly, inspectors found, and one person had clothing on back to front.
Some records, covering issues such as falls, were found to be inaccurate and relatives said felt they were not being listened to.
The home's operators Mead Medical Services Limited said it has submitted "a robust action plan" to the inspectorate.
A spokesman added: "The company is giving Kingsmead the upmost priority and commitment as we support our new home manager to address the areas of concern raised.
"We continue to work closely with all our partner agencies and residents' families in our mission to further improve the service provided."
A nursing home in Aberdeen has been criticised by inspectors after they found there was little respect for some residents' self esteem and dignity.