Abstract Essential oil yield and composition of wild and cultivated Calamintha sylvatica Bromf. ssp. ascendens (Jordan) P.W. Ball (Lamiaceae) were studied using GC and GC/MS. Essential oil yields were very similar in both conditions, although plant growth was greater in the cultivated plants. Isomenthone (36.8â43.3%) proved to be the main component of oil in both cases. Antifungal properties were tested for wild oil over nine domestic molds. The highest inhibition was achieved against Penicillum verrucosum, Monilia sitojihila and Aspergillus proliferans.