The New York Daily News quoted a police report that Hwang was walking on South Oxford Avenue near Lafayette Avenue when an unknown attacker slashed his neck from behind around 8:50 PM Nov. 30.
He was able to walk to Brooklyn Hospital, where he was treated and released. No arrest has been made in the case.
Hwang's Broadway credits include plays Face Value, Golden Child and Chinglish. He also wrote the librettos to musicals Aida and Tarzan, and updated Oscar Hammerstein II and Joseph Fields' book to Flower Drum Song for the 2002 revival.
Hwang is now a professor at Columbia University.