One major interest to analyse the extent ofN-acetyltransferase 1 (NAT1*) allelic variation in the human population stems to a great extent from the possible association of interindividual differences in the metabolism of aromatic amines with certain chemically induced diseases, including cancer. Considering the increasing number of mutations in theNAT1gene that are detected,NAT1* genotyping using conventional polymerase chain reaction (PCR) restriction fragment length polymorphism (RFLP) or allele-specific amplification assays has become complicated. We developed a rapid and powerful strategy allowing the full characterization ofNAT1* alleles. This method, based on single-strand conformation polymorphism analysis of a unique PCR product encompassing the entire intronlessNAT1* coding region along with additional flanking segments in the 5′ and 3′ untranslated regions, was then applied to DNA samples from 270 individuals. NineNAT1* allelic variants, including two novel (NAT1*28andNAT1*29), and 15 different genotypes were identified. This approach could be advantageously used in epidemiological studies to provide more definite data on suspected associations betweenNAT1* genotype and certain pathological processes.