Owing to their unique chemical and physical properties, inorganic-organic hybrid materials have been used in many application fields. In this paper, I have summarized the synthesis and characterization of various inorganic-organic hybrid materials with representative examples from my previous studies. These hybrid materials were used as adsorbents in heavy metal adsorption processes in order to solve metal pollution which is one of the most important environmental problems in the world. This review highlights the operation conditions such as pH, required dose, initial concentration, temperature, and treatment performance. Also, adsorption isotherms and adsorption kinetics are reviewed. This knowledge will provide the basis for the researchers who seek the new synthesis and application of hybrid materials in the future.