The objective was to distinguish between series of cultivars of Pelargonium xhortorum (zonal geranium), Pelargonium hybrids (seed geranium), and Pelargonium peltatum (ivy leaf geranium) using DNA amplification fingerprinting (DAF) demonstrating the utility of DAF for patent protection to prevent infringement of inventor's rights. Leaf tissue of 10 plants of each cultivar of seedling geranium was bulked for DNA extraction, and cutting and ivy geranium cultivars were bulks of five plants of each cultivar. Isolated DNA from different cultivars of a series were bulked together in their respective series. Seedling geranium series included Dynamo, Glamour, Multibloom, Orbit, Pinto, and Ringo 2000. Cutting geranium series included Designer and Showcase. Ivy geraniums were from the Guillou group. Amplification was with one of two octamer primers, followed by reamplifying with one of four different mini hairpin primers. Gels were visually scored for presence or absence of bands. The four primers generated 336 bands. The average number of bands (_1000 bp) per primer was 40. Twenty percent of bands were polymorphic and distinguished between each series of cultivars. Genetic relationships were evaluated by SAHN cluster analysis based on the distance estimator of Dice using the NTSYS-pc program (Numerical taxonomy and multivariate analysis system, version 1.8). Series were grouped according to species. Seedling geraniums were in one large group, the two cutting geraniums were grouped together and the ivy leaf geraniums were a separate branch.