Exports fell 5.3 percent in February from a year earlier, below the 1.4 percent rise forecast in a Reuters poll. In January, exports grew 3.1 percent.
The slowdown in exports was largely due to weaker demand for petroleum products, manufacture of metals and optical and scientific equipment, data from the country's International Trade and Industry Ministry showed.
Exports of mining goods fell 5.5 percent year-on-year in February, the data showed. Shipments of manufactured goods, which accounted for 83.8 percent of total exports, contracted by 4.3 percent.
Exports of palm oil, a major export commodity for Malaysia, fell 11.4 percent year-on-year, the ministry said.
Imports fell 9.4 percent in February from a year earlier.
February's trade surplus came in at 11.1 billion ringgit ($2.72 billion), compared with the 11.5 billion ringgit registered in the previous month.
Exports to China, a major trading partner, fell by 1.6 percent annually in February, a sharp decline from the 9.1 percent growth in January.
Shipments to the United States fell 8.9 percent, on slower exports of manufactures of metal, transport equipment and optical and scientific equipment. Malaysia reports trade data in ringgit.