Abstract: An intravenous catheter apparatus which protects a clinician from accidental puncture which may result in the transfer of dangerous infections. The catheter is introduced with the aid of a needle, which is thereafter withdrawn from the patient 3 s body into a protective housing without exposing the needle during any intermediate stage of the process. Means are provided for latching the housing in place after needle withdrawal, and for locking the catheter hub in place until that time. Withdrawal and locking are effected in one continuous motion.