Here we present a miniaturized assay, referred to as Carrier-Mediated Distribution System (CAMDIS) for fast and reliable measurement of octanol/water distribution coefficients, logD oct . By introducing a filter support for octanol, phase separation from water is facilitated and the tendency of emulsion formation (emulsification) at the interface is reduced. A guideline for the best practice of CAMDIS is given, describing a strategy to manage drug adsorption at the filter-supported octanol/buffer interface. We validated the assay on a set of 52 structurally diverse drugs with known shake flask logDoct values. Excellent agreement with literature data (r 2 =0.996, standard error of estimate, SEE=0.111), high reproducibility (standard deviation, SD<0.1 logD oct units), minimal sample consumption (10μL of 100μM DMSO stock solution) and a broad analytical range (logD oct range=−0.5 to 4.2) make CAMDIS a valuable tool for the high-throughput assessment of logD oct .