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 α-muurolol (13.2%), spathulenol (12.1%), α-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 Gramnegative bacteria by means of a modified agar-well diffusion method.S. aureus strain was found to be the most sensitive microorganism.