This article synthesizes work done over the past few decades to better understand the removal of organic contaminants by the coagulation process, alone and in combination with other processes. Published data demonstrate that coagulation can substantially reduce the concentration of certain organic contaminants found in drinking water supplies, and that an understanding of the fundamental mechanisms by which coagulation removes organic contaminants facilitates qualitative prediction of the types of contaminants likely to be removed and the effects of process control variables. Data also demonstrate that removal of organic contaminants by coagulation can be influenced by other processes, such as preozonation, and that coagulation can influence the removal of organic contaminants by subsequent treatment processes, such as filtration and activated carbon adsorption. Includes 143 references, tables, figures.