Oscillations in the local field potential (LFP) are abundant across species and brain regions. The possible role of these oscillations in information processing in the primary visual cortex (V1) of the macaque still remains largely elusive despite that V1 is one of the most extensively studied brain areas. To this end, we used chronically implanted, multiple tetrodes and recorded the spiking activity of single neurons and LFPs from area V1 of the awake, behaving macaque. Moving and static gratings of different orientations were used for visual stimulation. In agreement with previous reports we find that the increase of the LFP gamma-band power is a function of the orientation of the stimulus. Surprisingly though, there is only a weak correlation between the peak of the multi-unit spiking activity orientation tuning functions and the peak of the orientation tuning function of the gamma-band power of the LFP. There is however a different kind of relationship between spikes and LFP. Namely, the timing of the spikes is not randomly distributed in time but instead is locked to the phase of the gamma-band of the LFP. Specifically, the spikes of 60 out of 151 well-isolated single units showed significant phase locking to the LFP (P<0.05, circular Rayleigh test). On average, the spikes occurred on the downward slope of the LFP oscillation. In contrast to the presence of phase precession reported in the rat hippocampus, the phase tuning in V1 is stable over time. Specifically, the preferred phase of the spikes does not seem to change over time during the presentation of the stimulus. Moreover, the preferred phase is not significantly modulated as a function of the orientation of the stimulus (Figure A). This temporal structuring of the spiking activity of neurons in V1 could allow coding of information in the temporal regime (Panzeri & Schultz, 2001). In addition it could also potentially synchronize populations of neurons (Fries 2005). We are currently investigating these conjectures.