Microsatetlites have emerged as an important source of genetic markers for eukaryotic genomes. In this report, two wheat (Triticum aestivurn L.) genomic libraries were screened for several di-. tri-. and tetra-nucleotide tandem repeats. Clones containing (AC)n, (AG)n. (TCT)n. and (TTG), repeats were isolated and sequenced. On average, there was one (AC)n microsatellite every 292 kbp and one (AG) microsatellite every 212 kbp. The trinucleotide tatdern repeats (TCT) and ('I'rG) were about 10 times less common than the two dinucleotide tandem repeats tested and tetranueleotide tandem repeats were rare. Many of the microsate[lites had more than 10 repeats. The maximum repeat number found for (AC), was 36 and for (TCT)n was more than 50. The prevailing category of (AG) microsatel|ites from (AG), isolates was perfect repeats. About half of the (AC), microsatellites were compound repeats, while most of the (TCT). microsatellites were imperfect repeats. In a small sample. (TTG), microsatellites consisted mainly of compound repeats. The most frequently associated repeats were (AC)n with (AG)n. (TCT), with (TCC),. and (TTG), with (TGG)n. Among 32 pairs of microsatellite primers surveyed, seven.produced polymorphic products in the expected size range and theze loci were mapped using a hexaploid wheat mapping population or aneuploid stocks.