The Labour Department says a scaffolding worker died in Yuen Long on Thursday afternoon, after falling from a height.
It said the man had been erecting a truss-out scaffold on the external wall of a residential building. He was later declared dead in hospital.
"We will complete an investigation as soon as possible to identify the cause of the accident, ascertain the liability of the duty holders and recommend improvement measures. We will take action pursuant to the law if there is any violation of the work safety legislation," a department spokesman said.
Work at the site has been suspended.