Abstract To introduce a duplex PCR system consisting of the STR loci D21S11 and HUMFIBRA in forensic identity testing we analysed a Dutch Caucasian database of 205 individuals. The combined power of discrimination of the two loci is 0.9978 and there was no evidence for linkage equilibrium between the two loci (p = 0.91). However, we noticed departure from Hardy-Weinberg equilibrium for the D21S11-locus in our database (p = 0.03), but the differences between observed and expected D21S11 allele pair frequencies were of negligible practical significance in forensic calculations.