The consumer price index fell to 0.8 percent in the month, according to Statistics Canada.
Analysts had expected a rate of 1.0 percent after it was 1.2 percent in March.
Statistics Canada said the prices of meat, fresh vegetables, restaurant meals, passenger vehicles, clothing and footwear increased.
Gasoline, natural gas and mortgage interest costs fell.
At 2.3 percent, the core inflation rate used by the Bank of Canada in setting key lending rates, however, remained above the central bank's 2.0 percent target.
Its next rate announcement is scheduled for Wednesday.