The incident happened at Spring Street and Crosby Street in SoHo just after 8 a.m.
The 30-year-old man was pinned under the vehicle, and firefighters and EMS worked to rescue him.
He was rushed to Bellevue Hospital in critical condition.
The taxi driver who struck the pedestrian spoke to Eyewitness News reporter Anthony Johnson.
The driver, who was crying during the interview, said he was blinded by sun glare.
"There was so much sun, I couldn't see anything," Kha-Am Rahaman said. "I just brake and he fell. I saw the guy on the ground and called 911."
The victim sustained head trauma.
No charges are expected, and the crash is being investigated as an accident.