In this chapter, we briefly describe numerical approaches, based on computational fluid dynamics (CFD), developed to compute wave-induced ship motions. We do not claim completeness; instead, this chapter describes examples of numerical techniques commonly employed in this field. The listed references may be of help to the reader wishing to obtain additional details. Further on, we briefly discuss numerical errors and, specifically, procedures available to estimate discretization errors. Finally, we present an example of applying CFD to predict ship motions and loads in extreme seas.