Molybdenum disulfide (MoS2) nanoparticles were hydrothermally synthesized onto the surface of a cellulose nanofiber mat and demonstrated for the selective extraction and preconcentration of trace Hg(II) from aqueous media. Immobilization of MoS2 onto solid support restricts sorbent loss during a column operation. The surface morphology and chemical bonding of the prepared material were characterized by scanning electron microscopy, tunneling electron microscopy, and X-ray photoelectron microscopy. The selective sorption of Hg(II) is mainly attributed to the soft-soft interaction of Hg(II) with the S atoms of the MoS2. The experimental data shows good Hg(II) sorption capacity and was found to be 160.4 mg g(-1). The limit of detection and limit of quantification of the proposed method were found to be 0.09 and 0.30 mu g L-1, respectively. The accuracy of the method against the systematic and constant errors was confirmed by the analysis of the Standard Reference Material (>95% recovery with <5% RSD). Student's t-test values were found to be less than the critical Student's t value at a 95% confidence level. The developed method was successfully employed for the preconcentration and determination of Hg(II) in water samples.