Economists had expected an increase of 0.3 per cent, according to Thomson Reuters.
Statistics Canada said Wednesday sales were up in four of seven subsectors with growth led by the motor vehicle and parts subsector, which added 9.3 per cent to total $9.9 billion.
Excluding the auto-sector wholesale sales gained 0.4 per cent.
In volume terms, wholesale sales increased 2.0 per cent.
The wholesale sales data followed disappointing manufacturing sales figures released earlier this week that showed factory sales contracted 2.1 per cent in April.
The Canadian economy shrank at an annualized rate of 0.6 per cent over the first three months of the year and economists have been watching for signs of a rebound in the second quarter.
In addition to the gains in the auto sector's wholesale sales, Statistics Canada said Wednesday that the miscellaneous subsector rose 3.0 per cent to $7.5 billion.
Sales in the machinery, equipment and supplies subsector also increased 1.5 per cent to $11.3 billion, more than offsetting the declines in February and March.
The food, beverage and tobacco subsector fell 2.0 per cent to $10.4 billion.
Sales up in seven provinces, with Ontario accounting for most of the gain.
Inventories rose 0.5 per cent to $71.8 billion, the highest level on record.