This report provides an explanation of the chemistry of cementation systems and assistance in facilitating the choice of solidification agents and processing equipment. It reviews recent developments in cementation technology for improving the quality of cemented waste forms and gives a brief description of the various cement solidification processes in use. Contents: 1. Introduction; 2. Waste characterization; 3. Characterization of cement for solidification of waste; 4. Cement admixtures; 5. Chemical aspects of waste cementation; 6. Cement solidification processes; 7. Properties of immobilized waste forms.