A population study on thirteen short tandem repeat (STR) loci was performed on 223 unrelated Italian Caucasians. The DNA was amplified by PCR. Separation and detection of the amplified STR fragments was carried out by use of 377 automated system (Applied Biosystems Division/Perkin Elmer). All loci meet Hardy-Weinberg expectations, and the data show only five departures out of seventy-eight pairwise locus tests which is close to expectations of 5% (5/78 = 6.4%). When correcting for multiple tests, there is little evidence for departures from expectations between loci. The combined Power of Exclusion for the thirteen STR loci is 0.99999270. The results demonstrate that these loci will be very useful for human identification in forensic cases in Italy.