Phenolic acids are secondary metabolites of plants. Although less studied of other phenolic compounds such as flavonoids, the interest in their determination is also due to their antioxidant activity. In the past, gas chromatography coupled with mass spectrometry detection (GC–MS), as well as liquid chromatography (LC) coupled to UV detection, have been widely used for determining phenolic acids. Recently, the significant improvements in LC technology (for example, with the introduction of ultra-high performance LC systems) as well as in MS instrumentation (with the development of last generation, high resolution mass analyzers) have favored the development of LC–MS based methods with respect to GC–MS methods for the determination of phenolic compounds. The present review aims to provide an overview on the most recent works in the field.