Surface modification has been extensively applied to metal alloys to achieve extraordinary surface wettability for a wide range of applications. However, only limited research has been done on the surface wettability modification of 3D-printed metal parts. In this study, AlSi10Mg and Ti6Al4V parts fabricated using selective laser melting (SLM) were functionalized with silane reagent. With the assist of laser texturing or not, the surface showed different wetting behaviors, as the surfaces only treated by chemical solutions showed higher water adhesion (rose petal effect), while the surfaces gone through laser texturing exhibited lower water adhesion (lotus effect). The formation mechanism of the different wetting regimes was investigated. The results showed that the surface topography played an important role in determination of the wetting behavior. By applying surface topography parameters including Sa, Spc, and Sdr, the distinction in terms of surface topography between the surfaces with petal effect and lotus effect was quantitatively described.