There is increasing interest within the pharmaceutical industry in the development of proteins and peptides as drugs in addition to their use as biomarkers. Immunochemistry-based techniques have been traditionally used for the quantitation of proteins and peptides; however, LC-MS-based methodologies are being increasingly adopted as they offer several advantages. UHPLC is well established within the small-molecule community as a means to increase resolution and/or the speed of separations prior to MS detection; however, it is rarely applied to proteins or peptides separations. In this paper, current applications of UHPLC to such separations are reviewed, as well as considerations with regard to the effect of altering various chromatographic parameters.