Pattern of moult analysis, in Passer domesticus italiae, involves two problems: environmental information from unpredictable urban habitat and phyletic information according to hybrid nature between two species: P. domesticus and P. hispaniolensis. The paper outlines moult activities and its relations to fat and weight seasonal variations in Italian Sparrow Passer domesticus italiae. The first result in our analysis is that post-breeding moult in P. domesticus italiae does not differ from just known plumage substitutions pattern in all true sparrows. An anomalous pre-breeding moult was also observed. The dynamic of exchange, in the wing and tail feathers, is like to other passerine birds. High value of weight and subcutaneous fat during the winter is probably related to hyperphagia in preparation for cold months. Regarding to pre-breeding moult two hypotheses are considered: optimisation of spermatic perfonnance and phyletic information.