The developing countries all over the world are experiencing rapid population and economic growth especially in urban centers. The treatment & disposal of wastewaters is becoming more important as ever increasing population & urbanization threaten existing potable water supplies in many areas of the world. Although water hyacinth (Eichhornia crassipes) has proved to be a persistent and expensive aquatic weed problem in every part of the world it has ever invaded. Although water hyacinth is a serious aquatic weed due to its excessive growth rate but through utilization, it can be used for the treatment of industrial wastewater. The aim of this book is to present the experimental results of water hyacinth treatment of industrial wastewater mainly consisting of textile wastewater, stainless steel rolling mill wastewater and dairy wastewater. The samples of industrial wastewater treated with water hyacinth show that it is quite efficient in reducing the pollutional parameters such as BOD, COD, suspended solids, dissolved solids, heavy metals etc. The treated effluent is suitable for non-potable reuses in industries, agricultural or gardening etc.