Abstract: A process for obtaining fertilizer salts and organic substance concentrates of high nutritive value from industrial waste waters, in particular of waste waters of the agricultural, food processing and food preserving industries, with a high content of Totally Dissolved Solids (T.D.S.), includes the following operating phases:Automatic diversion of the high T.D.S. content waste waters from those of low T.D.S. content by means of a conductivity or density measuring instrument.Mixing of the high T.D.S. content waste waters with strong acids or bases, according to the composition of the waste waters, so as to form stable salts.Filtration of the so-formed solution for the purpose of eliminating the insoluble substances and precipitates.Concentration of the solution by means of evaporation.Crystallization of the concentrated solution.Separation by means of centrifugation of the fertilizer salts from the mother liquors containing organic substances of high nutritive value.