London, Mar 15 : The brief return of George Clooney to `ER' has given the long-running medical drama its best rating in two years, as the series draws to a close.

Clooney''s comeback episode, also featuring former regulars Noah Wyle and Eriq La Salle, saw a 23 percent increase in viewers, reports the BBC.

The show, which is based on an emergency room of a fictional Chicago hospital, was the most popular show on television in 1995, averaging 32 million viewers a week.

Clooney gained fame for playing Dr. Doug Ross, firmly cementing a place amongst Hollywood heartthrobs.

He left in 1999 to pursue a full time career on the silver screen, winning an Oscar in 2005.

The show in its 15th, and final series was created by the late Jurassic Park author Michael Crichton. (ANI)