The aim of the present study is to assess DNA damage in leaves of strawberry (Fragaria x ananassa Duch.) seedlings treated with different heavy metals (zinc, chromium, lead) using random amplified polymorphic DNA (RAPD) assay and analysis of total soluble protein content. For this purpose, strawberry seedlings were treated with 400 and 800 mu M Zn, Pb and Cr for 7 days. Thirty four RAPD primers produced 218 bands at molecular weight ranging from 183 bp to 5180 bp. Compared with control, RAPD patterns of heavy metal exposed groups showed differences in band loss, gain of new bands and increase and decrease of band intensity. The highest polymorphism rate (32.11%) was observed in 800 mu M Pb applied strawberry seedlings. To evaluate the alterations in RAPD profiles qualitatively, genomic template stability (GTS) was performed and the values were 75.08% and 69.59% for 400 and 800 mu M Zn treatments, 74.52% and 68.60% for 400 and 800 mu M Cr treatments, 70.11% and 63.78% for 400 and 800 mu M Pb treatments, respectively. Total soluble protein content in heavy metal-treated groups also showed a similar correlation to GTS values. RAPD analyses are useful biomarker assays to determine the genotoxicity induced by environmental pollutants such as heavy metals in plant model systems.