Frank Fritz, famous for his work on "American Pickers," is having some serious health issues ... because he's in the hospital after suffering a stroke.
Frank's condition doesn't sound too promising, with his former History channel show co-star, Mike Wolfe, asking for thoughts and prayers.
Mike shared Frank's health update Thursday on social media, saying ... "Now is the time to pray for my friend. Frank has suffered a stroke and is in the hospital. Please keep him in your hearts and thoughts."
Frank's longtime pal added ... "I pray more than anything that you make it through this okay. I love you buddy."
TMZ broke the story ... Frank stepped away from "American Pickers" over a year ago as a result of health problems that required back surgery, on top of already living with Crohn's disease.
Frank last appeared on "American Pickers" in a March 2020 episode.