Western larch (Larix occidentalis Nutt.) is an important ecological and commercial species in the Pacific Northwest. We isolated nine microsatellite loci with variable polymorphism ranging from five to 19 alleles per locus. Observed and expected heterozygosities averaged 0.42 and 0.64 and ranged from 0.11 to 0.83 and from 0.48 to 0.80, respectively. These markers, along with those already existing, will be useful for the species’ gene resource management activities.