A set of 100 canine microsatellite markers--83 dinucleotides and 17 trinucleotides--is reported. A study of their frequency in the dog genome showed that, while the frequency of the CA repeats is one (CA)n every 47 kb, the 10 trinucleotidic frequencies vary from one every 117 kb (AGG)n to one every 875 kb (AGT)n. Polymorphism analysis performed on 16 unrelated mongrel dogs showed that 80% of dinucleotides are polymorphic, while only 30% of the trinucleotides are so. Of this set of 100 markers, 56 have been mapped on the RHDF5000 dog/hamster whole genome radiation hybrid panel. Moreover, through systematic BLAST analogy searches of the microsatellite-containing clone sequence, three new dog genes could be identified, based on their human ortholog. All of the markers presented may prove useful in physical mapping methods, and polymorphic microsatellites in genetic linkage studies or parentage controls in dog.