He posted a pic of himself alive and well with his 30-year-old wife Crystal, as well as a poster and scene from the 1946 noir thriller, based on the Raymond Chandler novel.
'Tonight's Mansion movie was Bogie and Bacall in The Big Sleep, he wrote.
While celebrity death hoaxes a a dime a dozen nowadays, 2016 has been a particular brutal year for celeb lifespans, so the rumour that sparked on Friday spread pretty fast.
The media mogul had not posted on the social media site for two months, but on Thanksgiving retweeted a photo that had been posted by his son Cooper which featured father and son enjoying a holiday meal.
Cooper had shared the picture of himself and his dad - who is married to Crystal Harris - along with his fiance Scarlett Byrne and a female family friend and wrote: 'Happy Thanksgiving all.'
The Playboy legend - who was wearing his trademark red robe in the picture while tucking into a bowl of soup - didn't add his own comment when he retweeted the image.
Hope everyone is having a lovely evening with family and friends. Happy Thanksgiving all pic.twitter.com/bCcDLnsK3X
Hefner's last posting came in September, when he slammed speculation about his ailing health.
He quipped: 'I wish the tabloids had informed me a little earlier in the week that I'm sick. 'I might have cancelled my weekend plans.'
However, he hasn't been seen in public since May, and last month his ex-girlfriend Kendra Wilkinson-Baskett admitted she worries about his health 'every day'.
She said: 'Hef and I talked and saw each other actually a couple weeks ago.
'I'm not a medical person or any of that stuff...honestly he was there and we had a great talk and we were very happy to see each other.'
And iconic former Playmate Pamela Anderson recently admitted she finds it hard to see her pal these days because he is so frail.
She said: 'I remember when I first met him. He walked into the room and stole the show. It was beyond rock-star.
'Hef has always been a pioneer, setting the stage for all of us. When I saw him not too long ago, it was hard to see him in a walker.