The denim sector is booming worldwide, because of the spread of denim culture. All over the world it has brought with it a trend of fast-changing fashion. Denim washing has emerged as one of the important production routes toward meeting the fast-changing demands of the fashion market. There are huge ecological concerns, as this sector is enormous. Approximately 1500 gallons of water is needed to produce 1.5 pounds of cotton to make one pair of jeans. If this continues, soon it will pose a serious problem to drinking water supplies. It is therefore important to study the environmental impact of denim and find alternative processes. This chapter starts by describing the different types of denim washing techniques. In addition, it discusses the environmental impact of denim dry and wet washing techniques, and the importance of environmentally friendly washing techniques. It also describes the latest denim finishing technologies, comparing their impacts on the environment with those of the classic techniques. Further, the environmental aspects of auxiliaries and washing chemicals are reviewed, followed by a discussion of garment washing and finishing processes.