An atmospheric general circulation model (AGCM) sensitivity study has been performed with the ECHAM4 model forced by anomalous sea surface temperatures to investigate the role of the horizontal resolution (T42 versus T106) in determining the El Ni¿o/Southern Oscillation (ENSO) response in the North Atlantic/European region. The higher resolution has been chosen in order to represent more realistically the transient eddy activity that is supposed to play a crucial role in the signal communication to regions remote from the tropical Pacific. In contrast to the T42 experiments, the T106 experiments reveal significant changes both in the mean of selected atmospheric variables (sea level pressure, temperature, precipitation) over Europe and in the transient and stationary wave activity. A cyclone tracking analysis reveals a southward shift of the North Atlantic low pressure systems in the winter season during El Ni¿o events.