The piercing of the corporate veil - in Spanish: levantamiento del velo - is a common law legal institution in German and Spanish corporate law. So far, it has been scarcely addressed by European harmonization measures. First, the author examines the doctrinal foundations of this legal institution. Then, she investigates situations in which piercing the corporate veil is considered under German and Spanish law. The focus is on the important question for cross-border economic transactions of whether an entrepreneur in Germany and Spain must expect to be held liable through piercing the veil in similar situations and to a comparable extent.