Eighteen accessions of Mentha arvensis var. piperascens Holmes from the CIMAP collection (CIMAP/C01 to CIMAP/C18) consisting of wild collections and released varieties, their mutants, seed progeny and hybrids from the CIMAP gene bank were assessed for diversity through a combined morphochemical and molecular approach. Morphological characters, oil yield and essential oil components were taken into account to generate a cluster that outgrouped accession CIMAP/C05 from others. A total of 60 primers were used for RAPD and the tree generated after cluster analysis revealed accession CIMAP/C05 as the most diverse genotype. All the accessions exhibited differences in narrow range except CIMAP/C05. A wide range of compositional differences were observed in the essential oil profile of the genotypes indicating varying efficiencies of conversion of one component into other and/or existing metabolic blocks in the essential oil biosynthetic pathway in them. Copyright © 2009 John Wiley & Sons, Ltd.