The report gives results of an examination of the biological, chemical, and physical treatability of wastewaters from selected typical dye baths. Twenty systems providing a broad cross section of dye classes, fibers, and application techniques, were examined. Wastes, produced using typical formulations on a pilot scale, provided desired control and simulated plant conditions. Raw wastes were characterized. Treated wastes were evaluated for color and total organic carbon (TOC). Biological treatability was examined at several concentrations without seed, with domestic sewage, and with acclimated seed. Wastes generally were compatible with the biological process; color reduction was incomplete. No single treatment was effective for both color and TOC removal. Chemical treatment with ozone decolorized the wastes. Physical treatments included alum, lime, and activated carbon using jar tests. Disperse, vat, and sulfur dyes were most effectively decolorized by coagulation, and carbon was most effective for decolorizing reactive, basic, acid, and azoic dyes. A statistical evaluation of heavy metal content of dye baths and a compendium of dye bath additives and dyeing methods are included.