The general purpose of research was to evaluate the potential disinfecting effect of conservation/ restoration methods (deacidification and bleaching) and compare these results with effects of 2 commonly used in Poland methods of disinfection. The material was: 15 strains of fungi: Aspergillus ochraceus, Aspergillus versicolor (2 strains), Gliocladium catenulatum (2 strains), Penicillium ochraceum, Verticillium lamellicola, P. verrucosum var.cyclopium, Trichoderma harzianum, Aspergillus awamorii, Botryotrichum piluliferum, Paecilomyces variotii, Penicillium funiculosum, Aspergillus terreus, Penicillium spinulosum. Following 6 kinds of paper were tested: Whatman filtration paper, Whatman filtration paper sized with starch, Whatman filtration paper sized with gelatin, hand-made paper produced by Glaser (Stuttgart, Germany), acidfree paper Fabriano and standard printer/copy paper (Canon). Tested methods: - deacidifiation with calcium hydroxide water solution, - deacidifiation with barium hydroxide methanol solution, - bleaching with kalium permanganate water solution, - bleaching with chloramine T water solution, - disinfection with p-chloro-m-cresol methanol solution, - disinfection in vacuum-pressure chamber with ethylene oxide Experiment: 15 x 15 mm samples (3 repeats) of all six kinds of paper were infected with fungi and then exposed to the factors mentioned above exactly in the way it takes place during standard conservation/restoration. After exposition to agents the samples were incubated and after 3 weeks the growth on each sample was evaluated. The results from three samples for every set fungus/paper/method were interpreted in following way: if there was no growth at all, the method is effective (fungicidal) against fungus growing on specified substratum (paper). For 300 combinations fungus/conservation method/paper only the one treatment showed disinfecting efficiency: deacidifiation with barium hydroxide methanol solution was effective against Aspergillus awamorii growing on gelatin sized Whatman filtrating paper. The paper is chemically analogical to the old European papers sized with gelatin. However, the disinfection with ethylene oxide was not 100% effective either and the results of disinfection with p-chloro-m-cresol were much better (the most resistant to this method species was Botryotrichum piluliferum).