In spring 2008, in a nursery located in the Como province (Lombardy, northern Italy) leaf blight symptoms were observed on potted box plants (Buxus sempervirens 'Suffruticosa') followed by a sudden and severe defoliation. Diseased plants, had been imported from a Belgian nursery. These symptoms were suggestive of box blight, a new disease of the genus Buxus. The causal agent was isolated and identified through morphological, cultural and molecular characters as Cylindrocladium buxicola. C. buxicola was reported as a pathogen of the genus Buxus in the 1990s in the UK and New Zealand, and since then has spread throughout northern Europe. To our knowledge this is the first report of C. buxicola in Italy.