Conventional culture methods for the detection of Legionella species often require filtration and centrifugation to concentrate target organisms and subsequent decontamination prior plating on highly selective agar media. Aliquots of sample concentrates may subsequently be treated by heat or acid to reduce or eliminate high levels of non-target organisms that may be present in the sample. These treatments have been shown to reduce the total viable Legionella counts (TVLC). Immunomagnetic separation, utilizing beads coated with antibodies to a specific target organism, has been shown to be an effective strategy for isolating target organisms from complex environmental, food and clinical samples (Riffard et al., 2001; Yanez et al., 2005). This approach may eliminate the need for sample pretreatments and reduces the need for highly selective culture medium. The purpose of this evaluation was to compare the performance of Dynabeads® anti- Legionella using and an automated immunomagnetic separation protocol using the Bead Retreive™ with a standard protocol for the isolation and quantification of Legionella pneumophila in environmental samples. Includes tables.