Los Angeles - The curtain came down on long-running US medical drama ER Thursday night with over 17.4 million people tuning in to the final episode in the 15-year-old series, Nielsen Ratings said Friday.

The medical drama which propelled George Clooney to stardom earned a record 122 Emmy awards since debuting in September 1994 and at its peak averaged 32 million viewers per episode.

However ratings fell as competition from cable channels multiplied and fans of medical dramas switched to fresher shows like House and Grey's Anatomy.