"I can be perfectly happy living in the country, having a little farm and working occasionally," the actor tells the December issue of Best Life.
"If someone calls, I'll go to work. But I am a little tired of putting myself through hell just to get into the room to be prepared, to be professional and to let go of any kind of anger or frustration, and then not getting the part."
Last May, Dempsey bought a farm in Maine where he grew up. The purchase was a turning point, he says: "It was like, you know what? I'm done. I now know what I want."
Patrick Dempsey, who portrays Dr. Derek Shepherd on Grey's Anatomy, says coming to terms with fame â€" and 14-hour days â€" has been challenging.
"The show is like running a marathon. It feels like it never stops. The obligations you have for the show â€" it's relentless," he says. "The amount of exposure and the visibility ... it was certainly a big change for me."
Dempsey co-stars with Amy Adams in Disney's Enchanted, which opens this week. He'll next be seen in the romantic comedy Made of Honor in May.
"There's an audience who's watching Grey's Anatomy who expects something from you when they go to the box office, so you want to deliver that," he says. "I'm going to wait to see what happens with these movies, and then we'll make choices after that. You can't get too far ahead of yourself."
Dempsey, who has three small children with his wife, Jillian Dempsey, says his "family â€" and all of its joys and heartaches â€" is the grounding force."
"It's why you do everything," he says. "It's why you go to work, and why you put up with what you have to put up with, why you do what you have to do. Because you want to make a better life for them."