The polymerase chain reaction (PCR) has been used to amplify a region of the ZFX and ZFY genes from DNA in human blood and other tissues, for determination of the sex of an individual. In the present study DNA was extracted from the pulp of 21 male and 24 female fresh human third molar teeth. A region of the ZFX and ZFY genes was amplified by PCR and analysed by digestion of the amplified DNA with HaeIII restriction endonuclease. The digested PCR products were run on a 2 per cent agarose gel. Males were distinguished from females by having a fragment of 317 base pairs which was absent in females. Identification of the sex of the individual was 100 per cent accurate in each case. A blind study of random samples of the same teeth, used to assess the reproducibility of the technique evoked an identical result. This method provides an accurate alternative to skeletal measurements and histological staining techniques for the sexing of individuals from small amounts of DNA.