Appendicitis is a common surgical disease that often presents with vague, inconclusive symptoms. Despite the development of technologically advanced diagnostic modalities, perforation has usually occurred before the surgeon sees the patient. Morbidity, length of stay, and hospital costs associated with appendiceal perforation have not changed markedly in the past 50 years. To evaluate prognostic markers for severe appendicitis, we reviewed 18 years' worth of records of patients with appendicitis who were admitted to St. Elizabeth's Medical Center of Boston and found that the combination of history and physical examination has withstood the test of time. We found that advancing age, duration of symptoms for 36 or more hours, white blood cell count, shift left in white blood cell count, and fever were significantly related to severe appendicitis. An abnormal plain film was a marker if fever coexisted.