Ipsilateral horizontal eye movements were induced in monkeys at short latency by electrical stimulation of the paramedian zone of the pontine reticular formation (PPRF). Eye muscle potential changes occurred within 2.3-3 msec after PPRF stimulation. This is 0.5-1 msec longer than activation from MLF stimulation over monosynaptic pathways. Within limits the amplitude of the eye movements induced by PPRF stimulation was independent of eye position, the velocity was constant, and the amplitude and speed were linearly related to the frequency of stimulation. Depending on the strength, frequency, and duration of stimulation, eye movements similar to slow phases of nystagmus and pursuit movements, or saccades and quick phases of nystagmus could be induced by PPRF stimulation. In alert animals the eyes held the new positions of deviation for variable periods after stimulation. These periods of fixation were generally longer than several hundred milliseconds and were similar to naturally occurring positions of fixation. Previous studies have suggested that slow and rapid eye movements and positions of fixation in the horizontal plane are generated in the pontine reticular formation. The data are compatible with this hypothesis. Moreover, activity induced by the stimulating pulses appeared to have been mathematically integrated. It seems likely that one integration of neural activity in the visual-ocular or vestibulo-ocular reflex arcs probably takes place in the PPRF.