The essential oil was obtained by steam distillation from fruits of Iryanthera ulei Warb. growing in Colombia. The oil was analyzed by GC/FID and GC/ MS. The main components were a-muurolol (13.2%), spathulenol (12.1%), a-cadinol (7.8%), guaiol (4.0%), oplopanone (3.7%), 1,10-diepi-cubenol (3.4%) and limonene (3.3%) constituting a sesquiterpene-type enriched mixture. In addition, oil was tested for its antimicrobial activity against some Gram-positive and Gram-negative bacteria by means of a modified agar-well diffusion method. S. aureus strain was found to be the most sensitive microorganism.