The bank said in a statement that it believes that site "may be engaged in activities that are, among other things, inconsistent with our internal policies for processing payments."
It joins financial institutions including MasterCard and PayPal that have stopped handling payments for the site.
Reached by phone, Bank of America spokesman Scott Silvestri declined further comment to The Associated Press.
WikiLeaks responded with a Twitter message urging its supporters to stop doing business with the bank.
