In Italy over the last few years, numerous experiments in the field of disinfection of books have been carried out with ethylene oxide, formaldehyde and methyl bromide. Ethylene oxide was used for the treatment of flood-damaged books belonging to the National Library of Florence. Recently in the chamber of the Istituto di Patologia del Libro many tests were carried out with this gas, pemitting estimation of penetration power inside the books, and the effect of the disinfecting action time. Ten thousands of books were treated with formaldehyde and methyl bromide at the new National Library and the Angelica Library in Rome. An experiment was carried out to assess the diffusion of the fumigants in the ambients and in the books. The results obtained have clearly shown the possibilities and limitations of the application of formaldehyde and methyl bromide in book storerooms.