New York's Metropolitan Transportation Authority tweeted that there were outages at underground stations that were limiting transportation from the Bronx, Brooklyn and Queens into Manhattan. "The first thing you learn is, let's get all the facts, and then we'll assess what to do".
The New York City transit system said it was working with Con Ed to restore power in affected subway stations.
ConEd says there are 42,000 without power on the west side of Manhattan.
Media reports indicate that thousands are without power in parts of Midtown Manhattan and the Upper West Side.
NYPD and FDNY are on scene, the NYPD announced on Twitter.
A spokesman for the city fire department said they were responding to multiple calls about stuck elevators and power outages, going from midtown, near Times Square, and extending up to the Upper West Side, the area close to Lincoln Center performing arts complex.
Manhattan residents and visitors took to Twitter to post photos of the city without power, including eerie photos and video of pitch-black subway stations.
The outage also saw some Broadway shows cancel their Saturday evening performances, including Best Musical Tony victor Hadestown and King Kong.
Gainer also hit the road to see how drivers are handling the unsafe traffic conditions on Manhattan's West Side Highway.
Power company ConEdison confirmed the blackout: "We are responding to extensive outages on the Westside of Manhattan".
While trains are still running despite the outage, the stations without power are being bypassed by trains until power is restored.
The outage was having a widespread effect on the NY subway system, which was experiencing power outages in its stations, the agency managing the trains said.
Police officers waved people out of the Columbus Circle subway station around 7:30 p.m.
At dawn, the Manhattan skyline shows no lights due to a power blackout, New York, New York, July 14, 1977.
Street lights and traffic lights have been put out of action.