Abstract The volatile constituents of the fresh materials of Hypericum cordatum were isolated by hydrodistillation and analyzed by GC and GC/MS. The leaves produced 0.04% of a yellowish essential oil and the flowers did not. The main components of the oil were myrcene (40.18%), Î±-pinene (16.40%), and limonene (12%). The antibacterial activities of the oil against Saccharomyces aureus and Escherichia coli and the anti-fungal activities of the oil against the fungi Cladosporium cladosporioides and C. sphaerospermum were evaluated. The oil showed an antibacterial activity against the bacteria S. aureus and anti-fungal activity against the two fungi.