The amplified fragment length polymorphism (AFLP) technique was used to examine genetic variation among old and newly emerged individuals of Hyophorbe lagenicaulis (the Round Island bottle palm) on Round Island to assess surviving levels of diversity in the wild population and to evaluate the suitability of old cultivated stocks on Mauritius as a source of seed for reintroduction. The analysis of AFLP data for 48 individuals of H. lagenicaulis (individuals from Round Island and elsewhere), two H. verschaffeltii, two H. vaughanii, one H. amaricaulis and one H. indica yielded 81 variable and six monomorphic bands. Analysis of molecular variance (AMOVA) and Shannon's indices showed a high level of genetic variation within the wild population on Round Island and a smaller amount of genetic variation among cultivated individuals. A neighbor joining analysis resulted in an unrooted network of genetic distances in which the five Hyophorbe spp. were separated and much variation within H. lagenicaulis was recovered. The Round Island populations of H. lagenicaulis contain representatives of the genetic variation found within the species as a whole. However, a few individuals, both wild and cultivated, represent apparently rare AFLP profiles, and thus, if a more representative distribution of genotypes is wanted for the wild population, cultivated sources could be introduced to Round Island from Mauritian gardens and plantings. © 2011 The Linnean Society of London, Botanical Journal of the Linnean Society, 2011, 167, 301–310.