The entorhinal cortex (EC) is a critical component of the medial temporal lobe (MTL) memory system. Local networks within the MTL express a variety of state-dependent network oscillations which are believed to organize neuronal activity and synaptic plasticity during memory formation. The peculiar pattern of sharp wave-ripple complexes (SPW-R) entrains neurons by a very fast oscillation at ~200 Hz in the hippocampal areas CA3 and CA1 and then propagates through the "output loop" into the EC. The cellular effects of SPW-R in this downstream area are, however, unknown. We therefore investigated the activity of layer V (LV) principal neurons of the medial EC during SPW-R oscillations in horizontal mouse brain slices. Intracellular recordings were combined with extracellular monitoring of propagating SPW-R in CA1 and LV. SPW-R in CA1 were regularly followed (5–10 ms delay) by negative field potential deflections (~200 mV) without fast oscillation in the EC. At resting membrane potential (-71 ± 4 mV), LV neurons rarely fired action potentials. However, SPW-R in CA1 robustly elicited depolarizing synaptic potentials in 12/15 cells. These responses were superimposed by rhythmic activity in the ripple band. Amplitude of synaptic potentials correlated positively with amplitude of SPW-R in CA1 while delay time was short for large network events. Upon subthreshold membrane depolarization, SPW-R in CA1 regularly triggered spikes in LV neurons. Most discharges occurred within 10–30 ms after SPW-R peak in CA1, similar to the delay of electrically evoked synaptic potentials from stimulating CA1 axons. Our results suggest specific activation of EC LV neurons by SPW-R in vitro. Supported by BMBF 01GQ1003A (BCCN/Heidelberg/Mannheim, B3).