Sharp wave-associated high frequency (~200 Hz) hippocampal neuronal network oscillations, or "ripples", are thought to be involved in the formation and consolidation of episodic memory. Current theories propose that memory traces are represented by assemblies of principal neurons that are activated during ripple-associated network states in area CA1. Here, we were interested in the timing of excitatory and inhibitory activity underlying ripples. Using whole-cell in vivo and in vitro approaches we investigated synaptic input onto principal neurons during simultaneous local field potential recordings. Our results demonstrate the presence of both phasic excitation and phasic inhibition during ripples reflecting an exquisite temporal coordination of excitatory and inhibitory neuronal networks.