POCIS (Polar Organic Chemical Integrative Sampler) is a relatively recent integrative sampler developed to trap hydrophilic organic micropollutants in aquatic environments. Nevertheless, at present, there is no review dealing specifically with this tool. The aim of this paper was to compile information from numerous references based on POCIS in order to discuss on the evaluation of time-weighted average concentrations (calibration methods, sampling rates, performance and reference compounds...) and to critically review the different in situ applications (screening or quantifying micropollutants, coupling with toxicity tests), application domains (molecules analyzed, sampling media) and analytical protocols for POCIS (processing, analysis, exposure duration).