A heartless crook knocked a 75-year-old man to the floor and swiped $150 from him inside a Manhattan bank, cops said Thursday.

The septuagenarian was withdrawing cash inside a Citibank at Park Avenue South and 25th Street at 9:45 a.m. Saturday when the thief came up behind him, brandished an unknown object and demanded money, police said.

“I want your money,” said the crook, who knocked the man down and yanked his wallet containing cards, ID and the cash from his hands, according to cops.

Surveillance video from inside the ATM booth shows the elderly man sprawled on his back trying to kick away the thief, who runs out of the bank.

The attacker was last seen dressed in black with a gray backpack. Anyone with information is asked to call the NYPD’s Crime Stoppers Hotline at 1-800-577-TIPS (8477).