Banerjee's remarks came on the eve of the first anniversary of demonetisation.
"Demonetisation is a big scam. I repeat, demonetisation is a big scam. If a thorough investigation is conducted, this will be proved," the chief minister alleged on Facebook.
"Demonetisation was not to combat black money. It was only to convert black money into white money for vested interests of political party in power (sic)," she alleged.
Neither it brought back black money stashed abroad nor it could combat terrorism or help the country develop, Banerjee claimed.
"In all practical sense, it yielded a big, big zero," she said.
Due to demonetisation, "the country has already lost GDP worth nearly Rs 3 lakh crore. Crores of workers, particularly in the informal sector, lost their jobs. Farmers were left to starve. Over 100 people lost their lives", the CM claimed.
November 8 will be observed as Black Day to protest against demonetisation and the "unparallelled damage" it caused to the country and the economy, she said.