Grey's Anatomy Star Patrick Dempsey Almost Played Another Iconic TV Doctor

The casting process for "Grey's Anatomy" contains some of the long-running series' most fascinating lore. Sandra Oh's audition, for instance, almost landed her in a different role when she tried out for the part of Dr. Bailey. Justin Chambers, meanwhile, only joined the cast after the pilot had already been shot. And that's to speak nothing of Shonda Rhimes' ambitious color-blind casting technique.

When it came time to cast the part of Dr. Derek "McDreamy" Shepherd, a number of actors were considered, including Rob Lowe and Isaiah Washington, who went on to play Dr. Preston Burke. When Patrick Dempsey auditioned, he was sure he didn't get the part.

"I remember coming in and all the producers were there," the actor recalled to TV Guide. "I remember Shonda looking at me, and I was convinced she didn't like me. I was like, 'I didn't get that.'"

Immediately after reading for Dr. Shepherd, Dempsey headed straight to an audition for another TV doctor: Dr. Gregory House. But the path towards "House" was short-lived. Upon exiting the audition, the "Grey's" team got in touch. "When I finished that ['House'] audition, I got a call saying, 'They want you to read with the actress who's playing the lead role in this,'" Dempsey continued. "I remember asking Shonda what that was [about] and she said, 'I was figuring out how to put you in the show.'"

Casting McDreamy was a challenging feat for Shonda Rhimes. "You had to believe he was intelligent, so you can believe he's a brain surgeon. And while you're watching, you'd be like, 'I wish my boyfriend looked like that,'" she told the Chicago Tribune. "Patrick came in and he was just perfect." Even Rob Lowe admitted that Dempsey was the right choice. "Me in that part isn't as interesting as Patrick in that part," he told People. "If it'd been me [the fans] wouldn't have called me 'McDreamy,' they would have called me Rob Lowe."

Finding the right actor to play Dr. Gregory House was just as difficult, and it similarly attracted a number of stars. Denis Leary, David Cross, Rob Morrow, and Kyle MacLachlan were all in the running to play the narcissistic doctor. Hugh Laurie won over the executive producers when he sent in an audition tape he filmed in a hotel room bathroom. Laurie, who was on location in Namibia shooting "Flight of the Phoenix," insisted that the bathroom was the only place with adequate lighting.

It helped that Laurie nailed the accent, which is arguably the key to Dr. House's sardonic retorts and generally misanthropic disposition. When Bryan Singer, the director of the "House" pilot, saw Laurie's audition tape, he mistook him for an unknown American actor.

For Dempsey, it was a different sort of American accent that confirmed he made the right call. "I met Ellen," he told TV Guide of his chemistry test with Ellen Pompeo. "And her Boston accent lit me up because I was from Maine. So, I immediately had a great connection with her."