Three experiments were run to test whether newborns were able to discriminate different stress patterns in multisyllabic stressed Italian words that varied both in consonants and in number of syllables. A high-amplitude sucking procedure was adopted in which the experimental group heard 2 sets of stimuli alternating minute by minute, whereas the control group heard only a single set of stimuli. The results showed that stress patterns were discriminated in 2 disyllabic phonetically unvaried words (Experiment 1), in 2 trisyliabic consonant-varied words (Experiment 2), and in 2 sets of disyllabic words varied in consonants within and between words (Experiment 3). The alternation procedure proved to be suitable for examining newborns abilities of discrimination and categorization. It also lowered the participants rejection rate compared with the classic habituation procedure. The present results suggest that newborns are sensitive to words' rhythm, as carried by stress patterns, and that this prosodic information is salient even in the presence of substantial consonant variation.