The information includes names, account balances and in some instances medicare numbers.
Wayne Memorial Hospital in Honesdale sent out privacy notification letters on Friday. That means many people would have gotten them on Tuesday.
The missing information stems from a CD that was sent by certified mail but did not arrive where it should have.
As patients learned about what happened on Tuesday, many expressed concern at the unknown.
"You get a little nervous because there's so many people that are thieves that can take something and really do a lot of harm to people," Marty Ryan of Waymart said.
According to hospital officials, the CD containing patient information went missing in early December. The CD was sent in a package by certified mail to the hospital's medicare contractor in Pittsburgh.
The contractor got the package but it was damaged and the CD was missing.
Along with the U.S. Postal Service, hospital administrators have tried to track down exactly what happened but so far they don't think there has been any criminal intent.
"They (postal service) had lots of damaged packages and we expect that it was just a damaged package," hospital privacy officer Stacey Goodenough said. "There's no indication that there was any foul play involved here."
The information from 1,182 patients between 2007 and 2012 was contained on the CD. Many patients Eyewitness News talked to said they didn't fault the hospital.
"I have nothing but good things to say about this hospital. They're wonderful, very wonderful," Judy Gustin of Aldenville said.
Officials say anyone who got their hands on the CD could potentially use a patient's medicare ID number to get free healthcare if they don't have insurance.
"Of course there's a little bit of concern," Goodenough said. "You want to err on the side of caution."
Wayne Memorial Hospital has set-up a dedicated call center for the people who are affected.
The hospital is also offering some people one year of credit monitoring services just to be safe.