Polyproline II (PPII) helix peptides are attractive for their tunability, biocompatibility, and antifouling behavior. However, the mechanisms behind their properties still need to be fully understood. Here, we will discuss the impact of PPII peptide surface coverage and guest residue chemistry on antifouling behavior. A quartz crystal microbalance with dissipation (QCM-D) measures the adsorption of PPII peptides and fouling on gold surface. We discovered that the PPII peptide coverage on surface impacts fouling, where higher coverage is desired for lower fouling. In addition, the chemistry of a guest residue also significantly impacts fouling, whereas PPII propensity does not seem to have an impact. We also show that PPII peptides on gold can prevent the adherence of human mesenchymal stem cells. These results will help in designing high-performance, multifunctional, biomaterial coatings for use in tissue engineering and beyond.