BACKGROUND: The aim of gender verification test is to maintain impartiality among female competitors by excluding males in women's sports competitions. Some microscopic methods such as X-chromatin test and Y-chromatin test had been used for this purpose. Because of their known shortcomings, the methods were replaced with the polymerase chain reaction(PCR)-based test. In this report we describe the assay used in the gender verification during the '99 Kangwon Asian Winter Games. METHODS: Buccal smear samples of 126 female competitors were obtained. These samples underwent digestion with proteinase K, and were followed by boiling treatment with Chelex resin. PCR was performed to detect the sex determining region of Y chromosome(SRY) in order to confirm the femininity, and beta globin region was coamplified for confirming that the DNA was extracted from buccal cells. An X-Y homologous region encoded amelogenin was also amplified so that the femininity could be reconfirmed. RESULTS: No SRY and Y-amelogenin like sequences were amplified in any of samples of 126 female competitors analysed. CONCLUSIONS: Established gender verification method based on PCR amplification of Y chromosomal DNA seems to be superior to others. Sampling is simple. The procedure of extracting DNA is simple, rapid, and does not require multiple tube transfers. False positivity and/or false negativity appear to be less. It appear that this method is useful and reliable for gender verification in international sports events.