Damon was scheduled to be on-hand at the 2nd annual OneXOne Fundraiser to benefit the organization, which aims to alleviate the suffering of children worldwide.
Access has confirmed the emergency did not involve the actor's children with wife Luciana Bozan – daughters Isabella, 3; and Gia Zavala, 1.
No other details were immediately available.
Damon, who had been tapped as the ambassador for the event, has been a very vocal advocate for OneXOne, even appearing on the season finale of "Entourage" with a passionate plea to Adrien Grenier's character to donate to the cause.
Other celebrities scheduled to appear at Thursday night's event include Charlize Theron, Carlos Santana, Josh Groban, Jeremy Piven, Mia Hamm and David Arquette.
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