The New York-based Conference Board says Tuesday that its consumer confidence index fell to 60.6, down from a revised 65.4 in July.
Economists had expected a reading of 66.
The index now stands at the lowest point since November 2011 when the reading was at 55.2.
The indicator is widely watched because consumer spending, including major purchases like health care, accounts for 70 per cent of U.S. economic activity.
Despite several brief spikes, the index has remained well below the 90 reading that indicates a healthy economy — a level it hasn't touched since the recession began in December 2007.