A new disease of milkwort (Polygala myrtifolia) was observed on several commercial nurseries in southern Italy. Diseased plants showed wilting, stunting, chlorosis or loss of foliage, and rotting of the basal stem as well as the crown and roots. A Cylindrocladium species was consistently found associated with crown, basal stem, and root lesions. The etiology of this disease was proved on milkwort, by fulfilling Koch's postulates. Two hundred Cylindrocladium isolates were collected from the most important Sicilian and Calabrian ornamental production areas from different host plants. Isolates were identified as Cylindrocladium pauciramosum (teleomorph Calonectria pauciramosa) on the basis of their obpyriform to broadly ellipsoidal terminal vesicles, conidiophore branching pattern, conidium morphology, as well as mating type studies with tester strains of C. pauciramosum for selected isolates. This is the first record of this pathogen from Europe and it is the first report of C. pauciramosum on milkwort.