Short tandem repeat (STR) loci represent a rich source of highly polymorphic markers in the human genome which are useful for the purposes of forensic identification and determination of biological relatedness of individuals. Here, as a part of an ongoing extensive study, we report the analysis of a multilocus genotype survey of 642 to 870 chromosomes in the French Canadian Caucasian population of Québec at six STR loci. The loci HUMCSF1PO, HUMTPOX, HUMTH01, HUMF13A01, HUMFESFPS, and HUMvWA were typed using two multiplex polymerase chain reactions (PCR). Amplified DNA samples were subsequently analyzed by polyacrylamide gel electrophoresis followed by silver staining. The heterozygote frequencies of the loci range from 0.614 to 0.820 (0.661 to 0.818 expected) and the number of alleles from 7 to 12 per locus. Although statistically significant deviation from Hardy-Weinberg expectations of genotype frequencies was noted at some loci by one or more tests, in general, the genotype frequencies are well estimated from the product of allele frequencies at all loci. The most frequent six-locus genotype is expected to occur in the French Canadian population with a frequency of 3.50 by 10(-5) and together, these six loci have an average probability of discrimination of 0.9999985. The study presented here indicates that these six STR loci are informative genetic markers for identity testing purposes in the French Canadian Caucasian population of Québec.