Isaiah Washington

Actor Isaiah Washington was fired from the show when he used an anti-gay slur against a cast mate. (Andy Kropa/Associated Press)

ABC says Isaiah Washington will return to Grey's Anatomy for a guest appearance in May, seven years after he was fired from the medical drama.

Washington exited the series in 2007 after an on-set clash the year before, in which an anti-gay epithet was directed at another cast member at the time, T.R. Knight.

Washington's return as Dr. Preston Burke coincides with the announced departure of series star Sandra Oh at the season's end in May. Her character, Dr. Cristina Yang, was engaged to Washington's Burke at one point in the long-running drama.

The date of Washington's episode was not announced.

During the controversy involving him, Washington also used the epithet backstage at the 2007 Golden Globe awards. He publicly apologized and tried to make amends by meeting with gay-rights organizations.

He made a public service announcement, produced by ABC, urging tolerance for all.

"Words have power. The power to express love, happiness and joy. They also have the power to heal," Washington says in the message.

"When you use words that demean a person because of their sexual orientation, race or gender, you send a message of hate…. We have the power to heal and change the world by the words we use."