Bacterial infections are complex events. They are studied in a variety of simple model systems, using mammalian or non-mammalian hosts, all of which fail to reproduce fully the situation in infected patients. Each model presents a combination of conceptual, practical, and ethical advantages and disadvantages. In this review, we detail the use of Dictyostelium discoideum amoebae as a model to study Pseudomonas aeruginosa. More specifically, our aim is to explore what this additional model system can bring to our understanding of Pseudomonas infections. The study of interactions between Dictyostelium amoebae and Pseudomonas provides a view of the selection pressures exerted by environmental predators on Pseudomonas. It also represents a unique system to assess the virulence of very large numbers of Pseudomonas strains.