The mechanical behavior/properties and mechanical stability of nanoporous Au are very important aspects when assessing its potential as a functional material. Therefore, in this chapter, deformation mechanisms as well as unique mechanical properties such as ultrahigh strength are discussed in the context of ligament size and relative density. Tests using various deformation modes including uniaxial tension and compression further highlight the complex behavior of this macroscopically brittle yet microscopically ductile material. In the last section of this chapter, an overview of current modeling and simulation efforts is given, summarizing among others both ligament and cell size effects at the nanoscale.