A new analytical method for the simultaneous determination of phthalic, isophthalic and 14 long-chain dicarboxylic acids in ambient aerosols by ultra-performance liquid chromatography/time-of-flight mass spectrometry with negative-ion electrospray ionization was developed and validated. A fast and quantitative pressurized fluid extraction procedure with water as solvent was optimized using sampling filters spiked with a standard solution and experimental design to determine the influential factors and interactions. The extracts were analyzed without any further clean-up step. Chromatographic separation was achieved with a mobile phase consisting of 20 mM formic acid in water and methanol/acetonitrile (60:40, v/v). Excellent precision and accuracies in the MS mass measurements were observed. Matrix effects were investigated by spiking actual samples with a solution containing standards. The method was applied to air particulate reference materials and atmospheric samples collected by a low-volume sampler at a French urban background site.