This invention relates to the detection of Legionella, more specifically Legionella pneumophila, more specifically Legionella pneumophila serogroup 1, in a sample. Methods of detection, and assays and kits useful for detection, are also disclosed. The invention provides a method for identifying the presence, absence, or quantity of Legionella pneumophila serogroup 1 in a sample, the method comprising the steps of detecting the presence, absence, or quantity of at least part of the nucleic acid sequence of the lpg0768 gene or an expression product thereof, and correlating the presence, absence, or quantity of the at least part of the nucleic acid sequence of the lpg0768 gene or an expression product thereof, to the presence, absence, or quantity of Legionella pneumophila serogroup 1 in the sample.