The mother-of-two says she got a "super late start" in the industry, only landing her first roles in her mid-20s and admitted if she'd been younger, things may have been different.
"I probably would have done my time, then gone out to search for other things," she revealed.
But ultimately, Pompeo realised how difficult it would be if she left the show and tried to launch a film career.
"I was definitely aware of how challenging it would be to find other roles in my late 30s and 40s," she said.
"I thought, 'Why would I leave something that is super-successful and pays me great to search the landscape?' I decided that I would stay on Grey's and be grateful and try to ride it out for as long as I could."
And the actress has no regrets about her choice.
"I am very happy that I made the decision to stay. It's only gotten better with time."