The Long Island Rail Road train crashed around 8:30 AM (local time) at Atlantic Terminal in the heart of the New York borough.
"76 non life-threatening injuries reported at scene of LIRR train derailment, Atlantic Terminal Brooklyn," the New York Fire Department said in a tweet.
Passengers rushed out as smoke filled the tunnel. The impact bent the train's doors and smashed windows.
Some of the injured were brought out on stretchers.
Commuter Aaron Neufeld said on Twitter that the crash was "crazy," but added, "Seems only a few people are lightly injured."
In September, a train derailed during rush hour as it entered the station in Hoboken, New Jersey, near New York. One person died and 114 were injured.
An investigation into that incident, in which the train entered the station at unusually high speed, is ongoing.