We have attempted here to address the problems relating to the pathophysiology, identification and treatment of IPN. The diagnostic role of radiology and of examination of culture samples obtained under its guidance is stressed as the gold standard in all cases where clinical findings have yielded a suspicion of superinfection. Surgery remains the treatment of choice, though antibiotic prophylaxis (and perhaps, in future, also therapy) may play a basic role, that no one could have thought possible up until only a very few years ago. Table 2 is an attempt to summarize what appears today to be the most rational over-all strategy in the diagnosis and treatment of IPN.