The leather tanning industry is among the oldest in the world, having evolved from ancient times to the present day. This sector is notable for its ability to convert animal by-products, particularly from cattle, goats, and sheep, into leather through tanning processes. These processes, which date back to ancient history, have enabled humans to wear leather, primarily utilizing two methods: vegetable tanning, which employs natural plant extracts, and chemical tanning, often based on chromium. The effluents produced by tanneries are complex and rich in organic and mineral substances, including hexavalent chromium, a highly toxic compound for the environment. These discharges, which exhibit varying bio-physico-chemical characteristics over time, are often challenging to biologically degrade and, if not properly treated, can lead to significant pollution of waterways and surrounding ecosystems. The odor nuisances generated by tanning industries pose a significant barrier to their establishment and expansion in urban areas. Additionally, these industries are substantial consumers of water, with requirements ranging from less than 25 to over 80 L/kg of rawhide. To mitigate this pollution and prevent environmental impacts, it is crucial to enhance production technologies to optimize ecological performance, which includes improving the efficiency of chemical use, reducing water and energy consumption, and recovering or recycling generated waste. The optimization of water usage can be achieved through various methods, including strict monitoring of wastewater volumes, batch washing instead of using running water, minor modifications to existing equipment, the adoption of low-drift techniques with upgraded machinery, the reuse of wastewater in less critical processes, and the recycling of specific process liquors. Traditional soaking and liming processes account for over 50% of the biochemical oxygen demand (BOD) and chemical oxygen demand (COD) in tannery effluents. Several alternatives can be explored to replace sulfide, recycle lime/sulfide liquors, and implement techniques to reduce hair consumption. To mitigate chrome pollution, it is feasible to increase the levels of chrome fixed in the tanning bath while minimizing losses in subsequent stages. Additional strategies include recycling used chrome liquors, which also helps lower effluent salinity, and treating chrome-containing liquors with an alkali to precipitate chrome as hydroxide for potential reuse. Current regulations about the treatment and quality of tannery discharges are particularly stringent.