Production was also off 2.3 percent in the 27-member EU, the data branch of the European Commission said.
September's data follows gains of 0.9 percent and 0.5 percent in the 17-nation eurozone and the EU, respectively.
Production of durable consumer goods fell 4.3 percent in the eurozone, the countries that use the euro as currency, after rising 3.9 percent in the previous monthly report. Output of non-durable goods fell 2.8 percent August to September in the eurozone and 2.1 percent in the EU.
Production of energy fell 1.8 percent in the eurozone and 2.6 percent in the EU, the data office said.
Among the 23 countries from which data is available, production rose in four, lead by a 2 percent gain in Estonia. Production fell furthest in Ireland, down 12.6 percent and Portugal, down 12 percent.
Those were the only two countries with double-digit declines.
In the Netherlands, industrial production was unchanged.