Genomic fingerprints from DNA of fifteen environmental and clinical strains of Legionella pneumophila serogroup 1, isolated from diverse geographic areas of Greece, during the period 1986 to 1994, were generated with arbitrarily-primed polymerase chain reaction (AP-PCR) in order to use the discriminatory power of two arbitrary primers, BG2 and M13 Forward to clarify the relationship among the fifteen isolates. Both primers were found to have the ability to discriminate strains of the same serogroup, to identify strains related to each other even though they were isolated at different times. Therefore, AP-PCR using BG2 or M13 Forward as primers, appears to be a useful tool which provides a fast and simple method for epidemiological fingerprinting.