Three short tandem repeat (STR) polymorphisms characterized by PCR product length < 175 bp were investigated. D18S535 and D1S1656 contained a 4 bp unit as basic repeat motif, D10S2325 a 5 bp unit. The heterozygosity rates were 0.76 (D18S535), 0.88 (D10S2325) and 0. 90 (D1S1656), leading to a combined discrimination power of 0.9999. In contrast to D10S2325 and D18S535, which showed a homogeneous repeat array without any variation in the repeat motifs, repeat length and sequence variation was found for D1S1656. Robust typing results could be observed for all three STRs using highly degraded DNA.