Phage therapy for Pseudomonas aeruginosa infections has been used for more than 50 years. Controlled investigation into its use dates from the early 1990s when positive laboratory studies of local and systemic infection were followed by clinical studies: symptomatic improvement and phage multiplication were seen in a pet dog with otitis and a human with an infected burn. Antibiotic resistance has renewed interest in this approach. There have been recent positive reports in the treatment of experimental animal infection including systemic and respiratory infections. Phages have shown promise against experimental biofilms. Two small recent clinical trials in otitis, of dogs and of human patients have provided some encouraging results. Phage has potential in the treatment of antibiotic resistant infection by P. aeruginosa. Hence, full scale clinical trials are needed.