Japan's climate, with several months of high temperatures, and high humidity, is well suited to the growth of various kinds of fungi. They grow not only on food, wood, and textiles, but also on paintings. We have examined a variety of instances of deterioration caused by the growth of fungi on paintings and have isolated and identified more than a hundred of these fungi. Of these, the typical ones are Alternaria, Cladosporium, Fusarium, Aspergillus, Trichoderma and Penicillium. Since 1982 we have studied a fungicide-containing varnish to test its ability to inhibit fungal growth. The varnish, made from synthetic resin containing Vinyzene, a fungicide, was sprayed on about 100 paint samples. Annual observations have confirmed that it has a fungicidal effect. This paper reports on the effect of the Vinyzene-containing varnish on paint and its utility as a fungicide.