A new amide-functionalized silica stationary phase, Supelcosil ABZ−Plus, suitable for reversed phase HPLC applications, was characterized by X-ray photoelectron spectroscopy (XPS), solid-state29Si and13C CP/MAS NMR and FTIR. The degree of hydration of this material was found to be much higher compared to amide-functionalized silica phases prepared by acid chloride treatment of aminopropylsilylated silica reported earlier and also compared to conventional C18reversed phase columns. The liquid chromatographic performance of this ABZ+Plus column was found to be superior to the C18columns, especially for polar analytes. The enhanced selectivity and better peak shape with this ABZ−Plus material was attributed to greater compositional differences between the surface and mobile phases coupled with more effective shielding of residual silanols and a more oriented alkyl chain structure.