Emergency crews arrived at the Peak Downs coal site, operated by the BHP Mitsubishi Alliance, in central Queensland near Mackay about 5am on Friday.
A worker died while another suffered "potentially life-threatening injuries" and was taken to Moranbah hospital, Queensland Ambulance Service said.
Operations at the mine located in the Bowen Basin have been suspended as investigators head to the site.
''A worker has died and another has been injured in a serious incident that occurred at a Central Queensland coal mine earlier today," Resources Health and Safety Queensland CEO Claire Cooper said in a statement.
"Preliminary information indicates two vehicles collided at the site early this morning."
Ms Cooper said investigators and coal inspectors had been deployed to the site and would work closely with police and emergency services.
"Our thoughts are with the worker's family, friends and colleagues during this difficult time.''
Queensland's natural resources and mines minister Dale Last said details surrounding the incident were "still coming to hand".
"I have been advised that a worker at Peak Downs mine has lost their life and another has been seriously injured," he said.
"Details are still coming to hand, but my thoughts are with the friends, work mates, family of those involved, and the emergency services who attended - everyone deserves to go to work and come home safely."
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