Three mutations in the Lewis-negative gene, T59G, G508A and T1067A, have been detected by means of a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in 149 unrelated Japanese individuals. We found three common Lewis alleles-Le (without the T59G, G508A, and T1067A mutations), le1 (with the T59G and G508A mutations), and le2 (with the T59G and T1067A mutations) in a Japanese population. In addition, we also found one rare Lewis-negative allele, le3 (only with the T1067A mutation). The allele frequencies of Le, le1, le2, and le3 were 0.607, 0.275, 0.114, and 0.003, respectively. Our results were in accordance with those expected by the Hardy-Weinberg equilibrium. Some statistical parameters of forensic interest were also calculated.