Japan's economy contracted in the October to December quarter as a rising yen and floods in Thailand hurt businesses.
Gross domestic product shrunk by 2.3% during the period from an year earlier, much worse than 1.4% contraction that analysts had forecast.
Compared with the previous three months, the economy contracted by 0.6%.
The numbers are a big blow to Japan's efforts to recover from the earthquake and tsunami last year.
"The economy is slowing down more than what was expected before," Martin Schulz of Fujitsu Research Institute told the BBC.
"The slowdown of exports is taking a heavy toll on the industry," he added.