Official figures show that US wholesale prices soared 1.1% in March.
But the Labor Department said core inflation, which strips out volatile food and energy costs, rose by a much tamer 0.2%.
The monthly Producer Price Index (PPI) measures inflation pressures before they reach consumers. It showed headline inflation accelerating at a much faster pace than most economists had anticipated.
The inflation snapshot was released amid rising concerns about inflationary pressures, especially sharp spikes in commodity prices which have pushed world food prices higher.
Headline PPI inflation in the year to March was up 6.9%, while the core rate was 2.7% higher.