In this work it is reported the synthesis, characterization and hydrogen sulfide (H2S) adsorption of Co (II) and Cr (III) modified kaolinite. The modified matrices were prepared by cation exchange process. The pure and modified matrices were characterized by X-ray diffractometry, X-ray fluorescence, FTIR-spectroscopy and thermogravimetry. Based on X-ray florescence data, it was verified that the total amount Co(II) and Cr(III), incorporated to the clay matrix (expressed as oxides) were: CoO (20.1 %) and Cr2O3 (1.3%). The total amount of adsorbed H2S (gravimetric data) are: pure kaolinite (2.6 mg/g), K-Co (4.7 mg/g) and K-Cr (2.8 mg/g).