$17,193.34 of loose change was found by construction workers as they moved in on the Sands Casino Hotel in Atlantic City in New Jersey.
The coins were found mostly in and around the casino's slot machines, Jackpot website reports.
The cash had built up over the casino's 26 years of business, but the owners never expected an amount that large, anticipating only $8,000 of loose change from the floors.
Carmen Gonzales, a spokeswoman for casino operators Pinnacle said: "We never expected this much. It was just shocking. Some of the coins we had to pry up. They were stuck to the floor, they had been there so long. They were real gunky and dirty, and had become like part of the cement. We had to dig them out of the floor with a knife."
Builders were employed as the 2,350 slot casino was due for demolition in order for a $1.5 billion mecca to replace it.
The lost money does lawfully belong to Pinnacle, although New Jersey authorities will recoup their eight per cent for gamers' losses.
$17,193.34 of loose change was found by construction workers as they moved in on the Sands Casino Hotel in Atlantic City in New Jersey.