Exports fell by 12.2 percent on the year when adjusted for price swings and were 5.0 percent lower than in February when also adjusted for seasonal swings, the Federal Customs Office said.
Nominal exports stood at 15.2 billion Swiss francs ($13.07 billion), the country's trade surplus narrowed to 121 million francs, down from some 720 million francs in February.
All export sectors suffered, with the watchmaking industry reporting a 26.6 percent year-on-year export drop in real terms as consumers curb spending on Swiss timepieces.
Demand for Swiss products fell in almost all regions of the world, only exports to the United States and Canada rose by 6.4 percent in nominal terms.
Swiss National Bank chairman Jean-Pierre Roth gave a bleak near-term outlook for the economy last week, saying exports - usually the driver of growth - should remain weak.