The author traces the history of appendicitis through the successive stages of its evolution--from the early anatomic descriptions of the appendix by Leonardo da Vinci and Vesalius to Louyer-Villermay's recognition of the fatal course that appendiceal inflammation may take; through the confusion of typhlitis and perityphlitis, until Reginald Fitz at the end of the last century classified its pathology and the disease appendicitis was born. The author has described the efforts of the early surgeons as they grew to understand the symptomatology of appendicitis and to realize that only by early operation could the tragic outcome of delay be averted. Credit is given to those whose contributions have advanced the frontiers of surgery-- Lawson Tait was the first to diagnose and remove a diseased appendix in 1880 in England and Abraham Groves the first on the North American continent, in 1883, in Ontario. Within a decade, the early surgical treatment of appendicitis became established. The writings of men like Charles McBurney and John B. Murphy are shown to be as pertinent today as they were at the turn of the century.