BHP Billiton has been found guilty of failing to provide a safe working environment after the death of a man at a Port Hedland workshop in 2008.
Andrew McLaughlin was crushed by a scissor lift.
Magistrate Peter Malone has found the company failed to provide instruction and supervision or implement and enforce a suitable job hazard assessment.
The magistrate found that led to Mr McLaughlin's death.
The maximum penalty for the offence is $400,000.
The case has been adjourned for sentencing until March 19.
In a statement a spokeswoman for BHP says the company will take time to reflect on the legal aspects of the decision.
