Phospholipases are produced from a diverse group of bacterial pathogens causing very different diseases. In some cases, secreted phospholipases appear to be the major cause of pathophysiological effects. Yet in other cases, phospholipases are key virulence factors, contributing to bacterial survival or dissemination without causing tissue destruction. Perhaps the most intriguing aspect of phospholipases as virulence factors is their potential to interfere with cellular signaling cascades and to modulate the host immune response.