Sericea lespedeza (Lespedeza cuneata) is a Kansas statewide noxious weed that is spreading at an alarming rate. The genetic variation among different populations of this plant was investigated using the methodology of randomly amplified polymorphic DNA (RAPD)-polymerase chain reaction (PCR). Samples of sericea lespedeza were obtained at distinct sites throughout eastern Kansas and total DNA prepared from each. Four arbitrary primers were used individually in a RAPD-PCR and the combined amplification patterns used to generate a dendrogram. Sixteen plants from nine different populations were grouped into nine unique genotypic groupings using this method. These data indicate that significant genetic variation exists among the different populations of sericea lespedeza examined and that RAPD-PCR is a valid and reproducible means for the detection of these differences.