The 91-year-old is set to release new documentary You Can Call Me Bill, which will detail his incredible personal and professional life.
Speaking to Variety about why he has chosen to do the documentary, Shatner, who most famously played James T. Kirk in the Star Trek franchise – a role he first took on in 1966, said he has started to think about his mortality.
“I’ve turned down a lot of offers to do documentaries before, but I don’t have long to live," he said.
“Whether I keel over as I’m speaking to you or 10 years from now, my time is limited, so that’s very much a factor.
“I’ve got grandchildren. This documentary is a way of reaching out after I die.”
The film, directed by Alexandre O. Philippe, will premiere at the upcoming SXSW Film Festival in Texas.
Shatner has daughters Leslie, Lisabeth, and Melanie from three previous marriages and is a grandfather to five.
He previously said: “Being a grandparent is the greatest joy for me.
“I have the time now to grab a grandchild and talk, and hug and kiss them and make sure that I’m taking time to be with them and to give them some aspect of the things I’ve learned.
“Family life is totally encompassing,” he added to The Guardian in 2014. “I see my daughters every weekend. And we go off on holidays together – everything from skiing to snorkelling."
Shatner is currently with ex-wife Elizabeth Martin, who he reunited with three years after their $2million split.