This manuscript introduces a new family of cyclic acetal-terminated alkanethiols used to prepare self-assembled monolayers (SAMs) on gold. The new SAMs, which are designed as variants of the biocompatible protein-repellant surfaces generated from thin films of oligoethylene glycol (OEG) or polyethylene glycol (PEG), were characterized by ellipsometry, contact-angle goniometry, and polarization modulation infrared reflection absorption spectroscopy (PM-IRRAS). A preliminary study of protein adhesion was also performed using fibrinogen as a model protein. The interfacial structure and properties of the new SAMs were compared with those generated from OEG-terminated alkanethiols and from surface-grafted PEG, which have been described previously. The data show that the new adsorbates form well packed and conformationally ordered films with contact angles of water ranging from 67 degrees to 95 degrees, depending on the precise structure of the acetal terminus. As a whole, the new SAMs offer a unique strategy for studying and designing adhesion-resistant biocompatible inferfaces.