The “Prontuário de Fotógrafos e Casas Comerciais de Fotografia do Porto ~1840~1980” is the result of the research work of the students of the Master in History of Art, Heritage and Visual Culture of the Faculty of Arts of the University of Porto. Through several historical sources, we tried to map the evolution and distribution of commercial photography houses in Oporto, their activity time and their impact on the Urban History. Places of image production, affluence and influence, both of processes and practices, and as cultural poles, photography houses have suffered a mass extinction with the arrival of digital technology. This loss resulted not only in the end of these sites of sociability, but the visual memory associated with thousands of individuals who flocked to them. With this Prontuário, we hope to open the way to awareness about these image-makers, their historical and artistic importance, and their archives, some lost, others nearing their end.