A woman who arrived at a hospital for an appointment was told she had died as staff searched her medical records.
Sylvia Slingsby, from Thurnscoe, South Yorkshire, visited Barnsley Hospital on Friday.
She was told that she did not have an appointment and when staff investigated, they discovered she was down as being deceased in her records.
Barnsley Hospital has apologised for any distress caused and said the mistake was due to "human error".
Mrs Slingsby said: "When I gave them my letter they said that I didn't have an appointment that day.
"They looked it up on the computer and then they told me that I was deceased.
"When they told me that I was deceased I nearly collapsed. I went cold."
Mrs Slingsby, who went to the hospital with her daughter, said she has had no contact from the hospital explaining what had happened or an apology since the incident.
"We laughed about it but then we were mad," said Mrs Slingsby.
"We were talking about it in the waiting room and when I went to see the doctor she said that it was wrong and that they would have to do something about it."
A spokesperson from Barnsley Hospital said in a statement: "We are sorry for the distress caused to Mrs Slingsby.
"We are currently investigating the circumstances around this case and will put any necessary procedures in place to prevent this from happening in the future.
"Although we follow strict measures to ensure that medical records are maintained correctly, on this occasion the mistake was due to human error."