An I.V. catheter assembly and needle safety device are disclosed which allow for the safe removal of a needle from a catheter assembly. The safety device includes a locking assembly which includes lock housing a rotatable locking member and a locking clip. The needle and the locking member are configured such that withdrawal of the needle from the catheter assembly effects rotation of the locking member. The locking clip is positioned and configured to obstruct rotation of the locking member after the needle has been retracted within the housing to obstruct re-advancement of the needle.
