The passengers were caught at different ends of the Roosevelt Island aerial tramway which stalled because of mechanical failure.
In one gondola 46 passengers were stranded hanging over Manhattan's First Avenue, and 22 in another cable car swaying over the East River.
After repeated attempts to restart the tramway proved unsuccessful, police used a diesel-powered gondola to rescue the commuters over the river and a bucket and crane to bring down those in the other car.
The daring operation saw police teams remove a window from the tram and use a harness to swing passengers across a half-meter gap to the rescue gondola. It took four separate trips to complete the harrowing process.
Nobody was injured, although many passengers said they had felt extremely nervous when the gondolas first stalled.
"At first it was scary, and then, when we realised the tram was stable, it was just a question of waiting," said Jeanne Raichle.
"The problem was we really didn't know what was going on," she told reporters. "I thought we were going to fall," added 11-year-old Zachary Rothfeld.
The only commuter cable car in the United States, the aerial tramway connects Manhattan with Roosevelt Island, a tiny strip of land in the East River that is home to around 10,000 people.
The system was built in 1976 to ease the anger of local residents over delays in connecting the island to the city's subway system.
Since then, the two gondolas, each capable of carrying 126 people, have ferried some 20 million people on the four-minute journey to and from Manhattan.
The service has been suspended pending an investigation into what caused the mechanical failure.