The genotypes of the strawberry (Fragaria x ananassa), apple (Malus domestica) and Ribes species (R. nigrum, R. rubrum and R. glossularia), maintained in our Institute's collection and used in breeding programs, were screened for DNA markers. Twenty primers for RAPD (among 60 tested) and seven for ISSR (among 10 tested) were chosen as creating polymorphic DNA bands differentiating the investigated genotypes. Based on those identity markers, the genetic distance between genotypes was determined, and their relatedness was estimated. In many cases, both RAPD- and ISSR-based genetic similarity confirmed relatedness connected with biological origin and with the place where the cultivar was developed. However, some diversity connected with the technique used for molecular marker generation was observed. Generally, the similarity values based on ISSR data were higher than those based on RAPD. Parallel study using two data sets seems to enable a reduction in the number of potential mistakes connected with each method's, technical limitations and ensures more precise relatedness determination.