This report presents a single neurons operant conditioning paradigm which allows the quantification of operant control between neurons and monkeys. The operant task is for the monkey to change firing patterns of the neuron from phasic to tonic. In 60 neurons conditioned after the protocol had been standardized the following results were obtained. (1) For a fixed interspike interval target range, the time off target may be considered error, and this may be used as a parameter with which to judge operant neuronal control. (2) The degree to which the monkey could control a neuron was not correlative with the neuron's initial firing rate, firing rate variance, or pattern. (3) Neurons coactivated by distal arm muscle groups were, as a group, more highly controlled in comparison to neurons coactivated by proximal muscle groups. (4) Pyramidal tract neurons, as a group, appear more accurately controlled than non-pyramidal tract neurons. (5) The role of proprioception in response acquisition is discussed.