© The Classical Association 2000A long-lasting and sometimes acrimonious debate over the correct vocative form of second-declension Latin words in -ius began more than 800 years ago. For the past century most classicists have considered the matter to be settled, and little discussion on the subject has taken place. Yet the century-old conclusions we now so unthinkingly accept are based on very little evidence and are internally inconsistent in some of their details. The past hundred years have provided us not only with more Latin to work with, better tools for search and analysis, and a more complete knowledge of the history of the Latin language, but also with a new understanding and respect for the ancient grammarians and their views on the structure of their language. It is time to re-examine the ancient and modern views on the vocative of -ius words, to see whether any viable conclusions can be drawn and whether the ancient grammarians may have more to contribute than our predecessors believed.