Dr. Preston Burke (Isaiah Washington) is the former chief cardiothoracic surgeon at Seattle Grace Hospital. He attended Tulane University and then graduated first in his class at Johns Hopkins Medical School. He initially has a rivalry with Dr. Derek Shepherd (Patrick Dempsey) because they are both competing for the chief of surgery position, but they form a friendship after surviving a "Code Black" in the hospital.
During Season 1 he develops a relationship with Cristina Yang (Sandra Oh), but ends it at the beginning of Season 2 because he worries that it might compromise his chances of becoming chief. After learning that Cristina miscarried their child, Burke reconciles with her.
At the end of Season 2, Burke is the victim of a gunshot wound that affects his ability to operate. Although he initially undergoes surgery, he is left with a tremor in his surgical hand. For a time, he and Cristina hide his injury by having Cristina operate for him. After Cristina confesses to the chief, Dr. Richard Webber (James Pickens Jr.), Burke allows Derek to perform surgery and correct the problem.
During Season 3 he eventually proposes to Cristina, who accepts. At the same time, Burke is competing for the job of chief because Dr. Webber has announced his impending retirement. On the same day that he learns he hasn't been chosen as chief, he leaves Cristina at the altar. He explains that he's forced her to be someone she's not, instead of accepting her for the woman she is. Shortly afterwards, Cristina arrives at his apartment and realizes that he has taken all of his important possessions and left Seattle for good.
Burke is briefly mentioned in Season 4. A hospital employee posts a newspaper announcement that he has received the Harper Avery, a prestigious surgical award, at his new hospital.
"The only person that can keep a promise so big is God, and I haven't seen him pick up a scalpel lately."
"So, I have a question to ask. I checked the schedule and I noticed that both you and I are off tonight. I made reservations. I have a favorite restaurant."