South Africa's environment department says all rhinos and rhino horns in the country must now be microchipped to deter poachers.
The measure is contained in the National Environmental Management Biodiversity Act, which tightens regulations on the hunting of rhinos and export of their horns. It came into effect this week.
The Department of Environmental Affairs said in a statement Friday that even horns already in private possession must be registered at the owner's expense.
A report released in July by the World Wildlife Federation and other conservation groups said that the world trade in illegal rhino horns is nearing a 15-year-high, fuelled by high demand from Asia.
South Africa has lost 27 rhinos to poachers so far this year.