A total of 25 fungal species belonging to 10 genera were found associated with biodeteriorating picture walls at Lahore fort.  These included 13 species of Aspergillus, two species each of Alternaria, Drechslera and Fusarium, and one each of Acremonium, Curvularia, Helminthosporium, Mucor, Trichoderma, and Dematium. Alternaria alternata, Aspergillus niger, A. flavus and A. fumigatus were highly frequent and apparently major cause of biodeterioration. No much pronounced variation in fungal flora among the selected sites was evidenced. A great variation in variety of the fungal flora was, however, evident on 7 different type of growth media employed viz. corn meal dextrose agar (CMDA), Czapek’s dox agar (CZA), oat meal agar (OA), malt extract agar (MEA), potato dextrose agar (PDA), rose bengal agar (RBA) and sabouraud’s dextrose agar (SDA). Maximum fungal colony count was observed on CZA while highest fungal diversity was recorded on MEA. The fungal flora was isolated by two methods namely tape plate and scratch method, the later method appeared to be more reliable than the former.