In order to study the spatial patterns of genetic diversity of a clonal marine angiosperm, the seagrass Cymodocea nodosa, microsatellite markers were obtained by screening a genomic library enriched for the (CT) dinucleotide motif. Of 38 primer pairs defined, 15 amplified polymorphic microsatellites and are described. These loci identified a number of alleles ranging from two to seven, and showed expected heterozygosity ranging from 0.35 to 0.76, when a group of 40 individuals from Cadiz Bay in Spain was analysed. Additionally, we describe here the multiplexing conditions for 12 of these loci.