The existence and distribution patterns of microsatellites in the tiger puffer genome were evaluated utilizing DNA databank entries. Microsatellite regions amounted to only 0.96% of the 22.5 million bp included in the tiger puffer database. Di-nucleotide repeats were most common (90.1% of all microsatellites). Twelve microsatellite loci were isolated from the entries. Analysis of genetic polymorphism at these loci in the wild tiger puffer (n = 50) revealed a high degree of length polymorphisms, in which the number of alleles per locus ranged from 11 to 34. The expected heterozygosity was between 0.869 and 0.953. Mendelian inheritance was demonstrated in all but two loci (which seemed to include null alleles) by analysis of genotype ratios in the offspring of a single captive. Probability of identity of all loci ranged from 0.007 to 0.028. Band sharing index was low (0.119) in wild tiger puffer and high in the offspring of the captive (0.525). These results indicate the usefulness of the microsatellite markers identified for future population analyzes in tiger puffer.KEY WORDS: band sharing index, DNA database, fugu, microsatellite, null allele, Takifugu rubripes, tiger puffer, sample size.