Statistics Canada says the country's merchandise trade surplus grew to $5.3 billion in May, the largest trade surplus since August 2008.
The agency says the result was up from a surplus of $2.2 billion in April.
Exports rose 4.1 per cent in May to $68.4 billion as exports of energy products gained 5.7 per cent and the aircraft and other transportation equipment and parts category gained 34.2 per cent.
Meanwhile, imports fell 0.7 per cent in May to $63.1 billion.
Imports of consumer goods fell 4.7 per cent in the month, while aircraft and other transportation equipment and parts fell 22.7 per cent compared with April.
Export volumes for May increased 1.7 per cent, while import volumes fell 1.4 per cent compared with April.