Traditional descriptions of Italian phonology have occasionally suggested that some type of connection exists between "raddoppiamento sintattico" (RS) and the word internal consonant length contrast. (RS is defined as a systematic lengthening of the first consonant of the second word in a two-word sequence in certain syntactic and phonological environments.) This paper claims not only that some type of connection exists, but that there is a very specific type of relationship, and that the presence or absence of RS in a given variety of Italian depends on the presence or absence of contrastive consonant length in that variety. These claims are tested in two varieties of standard Italian, those of Rome and Milan. On the basis of these measurements, it is demonstrated that the patterns of consonant length created by RS do directly reflect the patterns of consonant length within words. The existence of RS in Rome reflects the existence of a word internal consonant length contrast in this variety of Italian, while the lack of RS in Milan reflects the lack of a word internal consistent consonant length contrast in the Milanese variety of Italian. It is also shown that while RS is not obligatory in those varieties of Italian that manifest it, the relative probability of its occurrence appears to be governed by certain syntactic factors. (Author/AMH)