The exact nature of the relationship between orbital and skull vault lesions of porotic hyperostosis has remained a controversial issue among anthropologists. Many researchers believe that lesions in both areas are related and have a common etiology; others remain unconvinced of any relationship and prefer to consider orbital and vault lesions as separate conditions with their own etiology. This paper explores the issue by comparing data on microscopic, macroscopic, radiographic, and demographic aspects of orbital and vault lesions from both clinical and anthropological studies. The results of these comparisons support the views that there is a relationship between lesions on both areas and that they share a common etiology.