AbstractAn update is presented covering the latest developments in the interfacing of liquid‐phase separation systems and mass spectrometers. The interfacing devices presented are those developed for continuous‐flow matrix‐assisted laser desorption/ionization, micro‐ and nano‐liquid chromatography/masspectrometry (MS), capillary electrophoresis/MS and on‐chip separation technologies/MS. From the information that can be found in the most recent literature on the topic, it is evident that the trend towards the miniaturization of separation and interface devices is gaining ground. This can be rationalized by the substantial gains in sensitivity for the detection and study of extremely low levels of analytes and especially of high molecular mass biopolymers. Copyright © 2002 John Wiley & Sons, Ltd.