The restoration of the Baroque cathedral of Kalocsa was led by Ernő Foerk between 1907 and 1912. During these years the facades of the church were renewed, a Neo-Baroque ambulatory was added, and excavations were carried out within the sanctuary and in front of the south facade. Based on these excavations, Ernő Foerk published theoretical reconstructions of the first and second medieval cathedrals and criticised the results of the previous research, conducted by Imre Henszlmann. Foerk, being also a scholar of the history of architecture, based his results on analogies. This paper intends to point out the elements which are outdated in the reconstruction of Foerk and his methodology that is still relevant.