This paper presents a comparative analysis of feed phosphates production processes using the Life Cycle Assessment (LCA) methodology and process analysis in the quantification of cumulated calculation. Three feed phosphates production processes were compared: a modified thermal process and two different low temperature endothermic units (one working in the "Bonarka" Inorganic Works (BIW) in Cracow and the other in the Phosphoric Fertilizers Works (PFW) "Fosfory" in Gdańsk). The LCA results indicated that the most advantageous technology is the feed phosphates production unit in "Fosfory". It was shown that LCA can be an efficient instrument for evaluating environmental impact, though it should be compared with other estimation methods.