Legionella longbeachae is one species of the family Legionellaceae. It was first isolated from a patient in Long Beach, California. It is found predominantly in potting soil and compost. In humans, the infection is sometimes called Pontiac fever. Human infection from L. longbeachae is particularly common in Australia, but cases have been documented in other countries including the United States, Japan, Greece and the UK. The infection can be very serious, often leading to hospitalisation and sometimes death. Like other Legionella species, person-to-person transmission has not been documented. However, unlike other species, the primary transmission mode has not been proven but it seems likely that it is inhalation or aspiration of dust from contaminated compost or soil that contains the organism causing legionellosis. Modes of transmission include poor hand-washing practices after gardening, long-term smoking, and being near dripping hanging flower pots. Awareness of a possible health risk with potting mix protected against illness. Inhalation and ingestion are possible modes of transmission. Exposure to aerosolized organisms and poor gardening hygiene may be important predisposing factors to L. longbeachae infection.