Pseudomonas aeruginosa sepsis rarely occurs in healthy children. In immunocompromised children, it usually carries a high mortality rate. Ecthyma gangrenosum is a known cutaneous manifestation of Pseudomonas septicaemia. Three paediatric cases of Pseudomonas aeruginosa septicaemia with ecthyma gangrenosum were retrospectively reviewed. The three patients were aged seven years, seven months, and five months, respectively. An underlying disease of hypogammaglobulinaemia was present in the oldest patient. Blood cultures grew Pseudomonas aeruginosa in all three patients. All underwent repeated wound debridement and received intravenous ceftazidime and an aminoglycoside for a minimum of two weeks. One needed colostomy and subsequent posterior sagittal anorectoplasty as a result of complete obliteration of the anal canal from the ecthyma. There was no mortality. In conclusion, Pseudomonas aeruginosa sepsis should be treated early. Recognition of ecthyma gangrenosum as a manifestation of this problem can allow early institution of the appropriate antibiotics before culture results.