A population study of Hungarian Romanies was carried out for the STR loci HumVWFA31, HumTH01, HumTPOX, and HumCSF1PO. After multiplex PCR amplification semi-automatic DNA profiling was performed using an ALF DNA sequencer. At the loci investigated there was little and no evidence for departures from Hardy-Weinberg expectations and linkage equilibrium, respectively. The allele sizing accuracy of the ALF DNA sequencer was increased to a high level (99.97% on average) by applying external and internal markers. Allele frequency distributions of the STR loci, with one exception, were significantly different between the Romany and other Hungarian population databases. On the other hand, however, only small differences in frequencies of individual phenotypes were found.