The latest consumer reading echoes a survey by Germany's ZEW institute earlier this month.
Market research firm GfK said its forward-looking index for March dipped to 10.0 points from 10.2 in February, slightly below analyst expectations.
Sub-indices measuring consumer sentiment about the future economic situation, income expectations and readiness to spend money all fell back in the latest survey of some 2,000 people.
"The change of administration in the United States and the considerable recent increase in inflation have put a damper on the generally positive consumer mood in February," GfK said in a statement.
Trump's pledges to rip up free trade deals and bring back jobs to the US have triggered fears about job security, it noted, particularly among respondents working in export-reliant industries such as car manufacturing and machine engineering.
Inflation in Europe's top economy meanwhile rose to 1.9 percent in January, the highest level since 2013.
Despite the concerns however shoppers remain willing to make purchases, the pollsters noted, comforted by record-low unemployment, high wages and low interest rates.
The latest consumer reading echoes a survey by Germany's ZEW institute earlier this month, which also saw investors fretting about political uncertainties.
By contrast, a closely-watched Ifo poll on Wednesday found that business confidence unexpectedly improved in February.