  We discuss the prospects of observing leptonic CP-violation at a neutrino
factory in the context of the standard three neutrino scenario. If the large
mixing angle MSW effect turned out to account for the solar neutrino deficit,
we show that observing an asymmetry between the $\reu$ and $\reub$ oscillation
probabilities would represent an exciting experimental challenge. We determine
the portion of the parameter space where an evidence could be found as a
function of the intensity of the muon source and of the detector size for
different baselines. We discuss the consequent requirements on a neutrino
factory. We address the problems associated with asymmetries induced by the
experimental apparatus and by matter effects. Finally, we emphasize the
importance of measuring two CP-conjugated channels in order to precisely
determine $\theta_{13}$.
