December's exports had been expected to grow 9%, according to 12 economists surveyed by Reuters.
Imports in the month grew 12% from a year earlier, data from the International Trade and Industry Ministry showed. Analysts were expecting 15.9% increase.
Malaysia recorded a trade surplus of 27.76 billion ringgit ($6.41 billion) in December.
($1 = 4.3340 ringgit)
(Editing by Ed Davies)