Colonial bentgrass (Agrostis capillaris L.) is a cool-season perennial grass. It is of great importance because it is adapted to fairways and tees of golf courses, and it has good low temperature hardiness and medium shade tolerance. Rough bluegrass (Poa trivialis L.) is a cool-season grass grown for sports fields, home lawns, and also winter overseeding on warm-season turf in southern United States. Our objective was to analyze genetic variation among each 27 accessions of rough bluegrass and colonial bentgrass by using randomly amplified polymorphic DNA (RAPD) markers. For colonial bentgrass, the Jaccard's similarity coefficients ranged from 0.13 to 0.72 based on RAPD data. The unweighted pair group method with arithmetic average (UPGMA) dendrogram clearly separated 26 out of 27 accessions into 3 clusters. A high cophenetic correlation coefficient (r = 0.82) indicated a good fit between the RAPD data matrix and cophenetic matrix. For rough bluegrass, the Jaccard's similarity coefficients ranged from 0.07 to 0.74 based on RAPD data. The UPGMA dendrogram revealed that 26 out of 27 accessions were clustered in 4 different clusters. The cophenetic correlation (r) value of 0.90 indicated a very good fit between data matrix and the cluster analysis. The clustering patterns of principal components analysis (PCA) corresponded well with the dendrograms in both colonial bentgrass and rough bluegrass. Since there was no similarity coefficient value close to one between any two accessions there was no duplication of accessions in colonial bentgrass and rough bluegrass germplasm collection.