Sales were down in 13 of 21 industries, "representing 86 percent of Canadian manufacturing," the data agency said.
The decline was largest monthly percentage drop since August 2009, as sales of durable goods dropped 1.6 percent and non-durable goods fell 3.2 percent in the month.
Sales of petroleum and coal products dropped 8.8 percent month to month to $6.3 billion, the lowest level in close to two years.
Sales of manufactured metals dropped 8.7 percent to $3.4 billion, the lowest level in three years.
Transportation equipment sales fell 1.7 percent in April after gaining for two months. In spite of the recent drop, sales in transportation have risen 14.2 percent from January.
On the positive side, sales of wood products rose 4.9 percent in the month and have risen in 11 of the past 12 months, hitting a level unseen since January 2007.
Sales of manufactured wood products were 38.5 percent higher than April 2012, StatCan said.