This article proposes the first systematic overview of some twenty-five medieval Iranian wall paintings in their architectural contexts (10–15th centuries). Its focus on the artistic technology of wall painting, epigraphic programmes, craftspeople’s workshops, decorative iconography and aesthetics is intended to promote their preservation. The study of these wall paintings contributes to the understanding of the history of religion, artists’ social statuses and patrons’ identities. The medieval Iranian monuments’ constructive and decorative chronology, and in some cases their dating, can be revised through scrutiny of their wall paintings. The article presents a model of the development of medieval wall painting technology and aesthetics. Recently published archaeometric analyses, combined with in situ documentation of wall paintings, facilitate discussion of wall painting production technology, craftspeople’s mobility, and regional characteristics of wall painting. The relationship between the arts of wall painting, carved stuccos, applied moulded and stencilled stuccos, and tile revetments is discussed to better understand the logic behind the use of wall paintings, their role in decorating monuments, and their position within the decorative hierarchy of multimedia decorative programmes. A contextualised interpretation of wall paintings’ aesthetics, function and meaning is proposed.