Abstract: A machine for inserting tire valves on wheel rims designed for receiving tubeless tires comprises pneumatic, electrical and/or electronic apparatus for logically programming a rim conveyor, apparatus for detaching a single rim and successively positioning same in waiting, operative and discharge positions, apparatus for exerting a pressure against the detached rim in the operative position for engagement with a rotary drive, apparatus for rotating the rim, apparatus for detecting the valve hole in relation to an axis ZZ of the emitting and receiving elements of a detection cell, apparatus for positioning the valve hole on an axis YY common to a centering spindle and to a cylinder carrying the valve to be inserted into the valve hole, apparatus for selecting a valve for each rim, apparatus for positioning the valve into the rim hole, and apparatus for holding the rim during the valve positioning operation.