Vietnamese customs officials seized more than 2,200 kg of ivory hidden in bags of beans imported from Mozambique during a check at Hai Phong Port on Thursday.
The shipment arrived at the port in northern Vietnam on November 29, but a local company named in the invoice as the receiver claimed it did not ordered any import.
Customs officers decided to open the shipment themselves on Thursday and found 835 pieces of elephant tusks.
They are investigating further.
Vietnam has banned ivory trade since the 1990s, and yet it has been fueled by the rising affluence in recent years and the demand for using ivories for decoration.
Animal rights activists say more than 100,000 elephants were shot dead for the ivory black market in Asia between 2010 and 2012.