Hg(II)-imprinting thiol-functionalized mesoporous sorbent was prepared by a sol-gel method and characterized by X-ray diffraction (XRD), FT-IR spectroscopy and nitrogen gas adsorption-desorption. The static adsorption capacity of the Hg(II)-imprinted and non-imprinted sorbent was 78.5 and 26.6mgg(-1), respectively. The breakthrough capacity was 4.46mgg(-1), and the relative selectivity coefficient for Hg(II) in the presence of Cd and Pb was 3.3 and 3.9, respectively. A new method using a micro-column packed with Hg(II)-imprinting thiol-functionalized mesoporous sorbent has been developed for preconcentration of trace mercury prior to its determination by inductively coupled plasma optical emission spectrometry (ICP-OES). The effects of pH, sample flow rate and volume, elution solution and interfering ions on the recovery of the analyte have been investigated. The limit of detection was 0.39ngml(-1) with a concentration factor of 150 times. The developed method has been applied to the determination of trace mercury in some biological and environmental samples with satisfactory results. The accuracy was assessed through recovery experiments and analysis of certified reference material.