Chief Constable Sir Hugh Orde is to press ahead with a pilot scheme for tasers despite being urged not to by the Policing Board.
Taser stun guns are used by police forces in Britain
Tasers are electric stun guns that hit their target with 50,000 volts.
The board voted on Thursday in favour of a motion that they should not be deployed until an equality impact assessment is completed.
Human rights experts who advise the Policing Board have expressed concern about the use of the stun gun.
Tasers are already in use by police forces in England, Scotland, Wales and the USA.
The PSNI is drawing up a business plan to buy 12 of the stun guns and wants to test them in a pilot scheme.
The board voted 11 to five in favour of a motion calling for no deployment until an impact assessment is completed.
"The only thing an officer would have to consider after taser sadly would be a firearm, which we know are far more lethal," said Sir Hugh speaking on Radio Ulster's Good Morning Ulster programme.
"No-one has died in the United Kingdom as a result of the use of taser. Sadly, as we know all too recently, someone was killed by police use of firearms."
Sir Hugh added that the stun gun is to be available to "specialist officers who will use it in pre-planned operations."