Los Angeles police spokesman Richard French says the 36-year-old actress's left hand and thumb were cut severely. Bialik's husband typed for her that she's in pain but her hand will remain intact.
Police say another car made a left turn and crashed into Bialik's vehicle shortly before noon Wednesday.
The three occupants of the other car suffered minor injuries and left the scene on their own.
French says no citations were issued.
"Blossom" star Bialik has been acting since childhood and stars in "The Big Bang Theory."
She was recently nominated for an Emmy for outstanding supporting actress in a comedy series.