Abstract: A blood-collection apparatus has a needle having a sharp front end and a sharp rear end, a mounting collar on the needle between its ends and a holder tube extending along an axis and having front and rear ends. A piston axially slidable in the holder tube is provided with a mount adapted to fit complementarily with the mounting collar with the needle rear end directed axially back in the tube. The piston normally is at the tube front end with its mount projecting axially forward from the tube. A flexible strand has a front end attached to the piston and a rear end projecting from the tube rear end. This mount is fitted into the needle's collar after the blood-collection operation is complete so that a pull on the strand retracts the piston back into the tube carrying the needle fitted to its mount.