Caprylic acid (CA), a naturally occurring eight-carbon fatty acid, has long been used as albumin stabilizer, non-IgG fraction precipitant and bactericidal agent in pharmaceutical industry. The mechanisms through which CA achieves its effects have been correlated with the molecule's protein/lipid binding capacity conferred by its octyl moiety. This article, following an initial review of CA's historical applications, introduces CA's relatively new application in downstream processing of monoclonal antibodies (mAbs). By taking advantage of CA mediated impurity precipitation and virus inactivation, it might be possible to develop a two-column purification process in replacement of the standard three-column process without compromising product quality.