An, D., Bykova, N. V. and Debnath, S. C. 2015. EST-PCR, EST-SSR and ISSR markers to identify a set of wild cranberries and evaluate their relationships. Can. J. Plant Sci. 95: 1155-1165. The cranberry (Vaccinium marcrocarpon Ait.) is a woody, evergreen, perennial vine with great potential for economic and health benefits. Selection and use of genetically diverse genotypes are key factors in any crop breeding program to develop cultivars with a broad genetic base. Molecular markers play a major role in selecting diverse genotypes. One hundred and two wild cranberry clones collected from four Canadian provinces and five cultivars were screened with inter simple sequence repeat (ISSR), expressed sequence tag-simple sequence repeat (EST-SSR) and EST-polymerase chain reaction (PCR) markers to validate the genetic diversity and relationships among them. EST-PCRs (0.54) and EST-SSRs (0.35) generated higher frequency of major alleles than ISSRs (0.08), but ISSRs presented a higher level of polymorphism and greater polymorphic information content and expected heterozygosity than EST-SSRs and EST-PCRs. Combined cluster analysis by the unweighted pair-group method with arithmetic averages (UPGMA) separated the wild clones and cultivars into four main clusters, which was in agreement with the principal coordinate (PCo) analysis. Analysis of molecular variation detected sufficient variations among genotypes within communities and among communities within provinces with ISSR (66 and 36%, respectively), EST-PCR (72 and 34%, respectively) and EST-SSR (72 and 34%, respectively) markers. These values were 71 and 35%, respectively, for combined analysis. Combined use of three types of molecular markers, for the first time in Vaccinium species, detected a sufficient degree of variation among cranberry genotypes, allowing for differentiation and rendering these technologies valuable for genotype identification in a diverse cranberry germplasm and for more efficient parental choice in the current cranberry breeding program.