This is a report on 108 cases collected from 1970 to 1987, in the same department, of surgically-detected pancreatic abscesses or pus-harboring collections. The purulent areas were either of a spreading pattern or represented a clearly localized mass. To the spreading pattern belong 47 cases of necrotizing pancreatitis, without discontinuity in the clinical course from the early toxic to the late septic phase, 4 cases of acute pancreatitis, initially in remission and later complicated by septic collections, and 4 cases which developed after an acute attack of chronic pancreatitis. The abscess pattern was made up of 19 each of pseudocysts and predisposing pancreatitis, 10 cases of chronic pancreatitis, and only 5 necrotizing "nonstop" pancreatitis. The surgical treatment in all cases consisted of multiple drainages and postoperative irrigation. We exclude 3 cases of associated open packing. The etiological, clinical, and biochemical features of each group of patients are reported and discussed. Computed tomography availability seems to be the most important improvement reported as regards diagnosis and surgical tactics. The overall mortality rate was 15.7% with a significant difference between the 2 patterns (23.6% for the spreading pattern versus 7.5% for the abscess pattern). On the basis of this experience, it is possible to establish a relationship between the gross appearance of the collection and the underlying pancreatic disease with differences in terms of prognosis, morbidity, and mortality. Finally, a simple nomenclature can be chosen which is capable of distinguishing between the diverse pancreatic purulent collections. While the presence of pus may characterize the course of severe acute pancreatitis in many cases, the low incidence of "true" pancreatic abscess is emphasized.