the present work aimed to study the chemical composition and bioactivity of the leaf essential oil of cupressus sempervirens l. and cupressus lusitanica mill. (cupressaceae) on mycelial growth and germination of colletotrichum fructicola conidia at the essential oil concentrations of 0.1, 0.5, 1.0, 1.5, and 2.0 ul.ml-1. the essential oil of c. sempervirens presented -thujene as the major compound (31.4 wt.%), whereas c. lusitanica essential oil was composed mainly of -pinene (22.7 wt.%). the bioactivity tests showed that both essential oils were ineffective in controlling adult c. fructicola individuals at the tested doses. however, antifungal activity of the oils against germination of the conidia was observed, in which c. sempervirens and c. lusitanica essential oils inhibited 50 % and 38 % of c. fructicola conidia germination at the concentration of 2 ul.ml-1. morphological alterations of hyphae were also observed after exposure to c. sempervirens essential oil at the dose of 2 ul.ml-1.