This study explores the spontaneous acquisition of Italian inflectional morphology by three children (age range I;4-3;O). Longitudinal, free speech samples are examined, focusing on the development of the morphological paradigms of Italian verbs, pronouns and articles. Data analysis is conducted using criteria appropriate to allow reliable cross-linguistic comparisons with data from English. By this means we evaluate the plausibility of a nativist, parameter-setting account of language development in Italian and English, as recently proposed for these two languages. Results show that the general developmental patterns observed in Italian are not significantly different from those found in English. These findings are not consistent with current interpretations of parameter-setting accounts of language development. Alternative explanatory models are discussed.