In considering the portraits of Ostia between the mid-third and sixth centuries AD, this work intends to complete the research inaugurated by the unforgettable Raissa Calza. In the first two volumes, published respectively in 1964 and 1978, the scholar analyzed the testimonies known up to 250 AD, providing an important contribution to the knowledge of Roman portraiture, and of Ostia in particular. Guido Calza's wife had identified and preliminarily filed, in typewritten form, also numerous portraits kept in the Ostiense Museum attributable to the last centuries of life of the port city, in the perspective of a last volume which unfortunately, also due to the serious difficulties of the last years of studious, she could not see the light. The awareness of the relevance of late antiquity materials from Ostia led the writer to undertake, already in 2004, the research whose results are presented here. The long time that has elapsed has been, as for each one, full of events and changes of various signs; and other studies and engagements have sometimes taken over. At the same time, however, the knowledge on late ancient Ostia and on the sculptural production of these fateful centuries became more and more extensive and deepened, thanks to the growing interest in that historical period developed in recent decades. These new data allow us to tackle the theme of the latest portraiture in Ostia from a new and stimulating multiplicity of perspectives. The volume was therefore able to be enriched with greater complexity, addressing the subject of the research in constant dialogue with the evolution of knowledge on urban planning, society and the economy of Ostia and Rome itself, between 250 and 500 AD.