The aim of our study was to evaluate the genetic relationship of Rhododendrons from Rhododendron collection at Tomaszkowice in Pogórze Wielickie. Leaves and leaf buds of three evergreen Asiatic species: R. aureum, R. brachycarpum, R. purdomii, six cultivars from Catawbiense Hybridum group (R. catawbiense): Catharine van Tol, Nova Zembla, Album Novum, Boursoult, Old Port, Hachmann’s Charmant and one cultivar from Yakushimanum Hybridum group: Koichiro Wada were investigated. Two plants from each accession were analysed. DNA was isolated by Ziegenhagen and Scholz [1998] protocol, dedicated to the difficult species in terms of high quality DNA extraction. After isolation, DNA was amplified with 19 RAPD primers. We obtained 255 RAPD markers and worked out a dendrogram, which illustrated the level of genetic diversity among the tested plants. Our study confirmed a close relationship between rhododendrons from Catawbiense Hybridum group. Another group was constituted by R. aureum and R. purdomii. The third group consisted of R. brachycarpum and Koichiro Wada cv.