In the opportunistic pathogen Pseudomonas aeruginosa a cell-to-cell signaling circuitry regulates the production of several major extracellular virulence factors. This interbacterial communication system allows P. aeruginosa to produce these virulence factors in a coordinated manner that overwhelms the host defense mechanisms. This article gives an overview of our present knowledge of the complex cell-to-cell signaling circuitry of P. aeruginosa and tries to outline its importance in the pathogenesis of acute P. aeruginosa infections. New therapeutic strategies, based on the blockage of this circuitry, are presented.