A 53-year-old crane operator died in Dandenong South after he was crushed by steel beams weighing several tonnes at about 11.15am.
It is understood a coupling failed, causing the beams to fall on the worker.
Less than three hours later in Kyabram, a 56-year-old worker died after a tractor-spreader combination he was operating overturned.
It is understood the man was driving the vehicle on a road when it jack-knifed and rolled at about 2pm.
The two deaths bring the workplace fatality toll to nine for 2022, six fewer than at the same time last year.