Euro zone economic growth halved in the second three months of 2016 to 0.3%, according to Eurostat.
In the year to June, growth came in at 1.6% pointing to a slowdown in the euro zone ahead of the vote by Britain to leave the EU.
A mild slowdown in Germany was overshadowed by a surprise stagnation in Italy.
The outcome offered scant hope of a decisive rebound for the currency bloc as a whole any time soon.
The official data showed that a burst of activity at the start of the year was fleeting and more stimulus may still be required from the European Central Bank.
In the biggest economy, Germany, gross domestic product grew by 0.4%, marking a 3.1% pace compared with the same period last year - the strongest annual figure in five years.
While slower than the start of 2016, growth was boosted by exports as well as consumer spending, putting Germany's performance and prospects ahead of many of its peers.
In Italy, the euro zone's third-largest economy, there was no growth at all in the second quarter, as industry and domestic demand flagged.
Preliminary data for France, the second-biggest euro zone economy, showed no growth either.
In the Netherlands, the picture was much better, with 0.6% growth in the second quarter, driven by services as well as decent domestic demand, particularly in housing, and export performance.
Previously reported data for Spain showed 0.7% growth in the second quarter.
Economic growth even picked up in Greece to 0.3% on resurgent tourism, an improvement on the first quarter, when the economy shrank by a revised 0.1%.
