Abstract: An apparatus for grinding hypodermic syringes or needles, IV needles and other medical waste into relatively fine particles. The apparatus includes a housing having a case therein defining an inlet and an outlet. A plurality of rotors are disposed in the case, and each of the rotors has a plurality of radially outwardly extending teeth therein which interact with teeth on the other rotors to grind the syringes or needles. A discharge valve is provided for controlling the flow of particles discharged from the case. The teeth on the rotors are longitudinally and circumferentially spaced. Generally, the teeth on at least one of the rotors extend between the teeth on another of the rotors. Also, the teeth on at least a pair of the rotors have angled sides which are angled in opposite directions such that the angled sides of the teeth on one rotor generally face, and are aligned with, the corresponding angled sides of the teeth on the other rotor.