In the present study apressure-assisted MEEKC method with reversed-polarity using a conventional CE instrument with UV detection and uncoated fused silica capillariesis validated as a high-throughput methodology for the lipophilicity determination of the neutral species of acidic compounds(pKa> 3.5).After the calibration of the system with four standard compoundsof known log Po/w, mass distribution ratios (log kMEEKC) of new molecules can be directly converted into log Po/wvalues by means of a simple linear equation (log Po/w=a·log kMEEKC+b). The method was internally and externally validated for a log Po/wrange between-1.54 and4.75, with higheraccuraciesthan conventional liquid chromatographic methods.