The Sentix euro zone index fell to 17.4 points from January's 18.2. The February reading from the Frankfurt-based research group was exactly in line with the consensus forecast in a Reuters poll of analysts.
"Investors are reacting to Donald Trump's first official acts and see in these a burden for the global economy," Sentix said in a statement.
Investors viewed the euro zone's current conditions more favorably, with a sub-index rising in February to 20.5 - the highest since May 2011 - from 16.5 in January.
Expectations for economic developments in the euro zone deteriorated, slipping to 14.3 from 20.0. Sentix noted, however, that the February expectations reading was still above December's reading of 11.8.
An index tracking Germany, the euro zone's largest economy, fell to 31.3 in February from 33.1 in January.
Trump has said the European Union has become a "vehicle" for German interests and predicts that more member states would leave the bloc as Britain did last June.
Trump has also warned German car companies that he would impose a border tax of 35 percent on vehicles imported to the U.S. market. His top trade adviser has accused Germany of using a "grossly undervalued" euro to gain advantage over the United States and its own EU partners.