the composition of essential oils from leaves, stems and fruits of piper aduncum, p. arboreum and p. tuberculatum was examined by means of gc-ms and antifungal assay. there was a predominance of monoterpenes in p. aduncum and p. tuberculatum and of sesquiterpenes in p. arboreum. p. aduncum showed the richest essential oil composition, including linalool. the essential oils from fruits of p. aduncum and p. tuberculatum showed the highest antifungal activity with the mic of 10 ug as determined against cladosporium cladosporioides and c. sphaerospermum, respectively. this is the first report of the composition of essential oils from p. tuberculatum.