A retractable obturator trocar with a puncturing tip is provided. Preferably the obturator includes a safety shield covering the puncturing tip in an unarmed position and permitting the tip to extend distally from the safety shield in an armed position. The obturator preferably includes a spool retracting mechanism which causes the distally extended obturator to retract into the safety shield when a force is applied to the puncturing tip. The obturator may also be manually disengaged. The safety shield and obturator preferably extend out of the distal end of the cannula whether the trocar is armed or unarmed.