The Italian noun was formed during the transition from Latin to Italian as a consequence of the disappearance of the cases in Latin. The most important changes were the phonological ones that contributed to the loss of cases and, consequently, led to the changes in the nominal system. The nouns, therefore, have only one, invariable form, while the cases in Italian are expressed through prepositions, articles or the position of the word in a sentence. The goal of this master thesis was to analyse the way in which the noun, its forms, categories, and usage are presented in the most important Italian grammars written from the 15th to the 20th century. Eight grammars were analysed, one for each century, except for the 17th and the 18th century for which, due to an abundant grammatical production in this period, two grammars were taken into consideration. The analysed grammars are: Grammatica della lingua toscana, i.e. Grammatichetta Vaticana from Leon Battista Alberti (1437-1441), Le prose della volgar lingua from Pietro Bembo (1525), Della lingua toscana from Benedetto Buommattei (1744), Regole ed osservazioni della lingua toscana from Salvatore Corticelli (1825), Grammatica ragionata della lingua italiana from Francesco Soave (1840), Regole elementari della lingua italiana from Basilio Puoti (1834), Grammatica italiana dell’uso moderno from Raffaello Fornaciari (1879), and Grammatica italiana from Salvatore Battaglia and Vincenzo Pernicone (1951).