Tapioca starch processing requires large volumes of water. It also generates a large amount of solid waste and wastewater. The Department of Industrial Works, Thailand has launched a program to develop pollution prevention measures for tapioca starch plants. This study, as a part of this program, shows that the implementation of clean technology in the eight selected tapioca starch-processing plants can successfully reduce water consumption and sources of wastewater. The proposed measures of clean technology include good housekeeping, reuse of the wastewater from a polishing pond for plant cleanup, and recycling of water in the production line. In addition to water conservation measures, a technological change by replacement of conical screen extractors with vertical screen system can contribute to production cost savings. Recovery of biogas from a wastewater treatment system can also be another alternative option for energy use in tapioca starch plants. The companies that have implemented these proposed clean technology options show success in improvements of consumption efficiency of raw materials and energy resources, and reduction in production cost.