abstract the composition of the essential oils from leaves of croton jimenezii standl, et valerio, from two locations in costa rica were examined and compared. the oils were analyzed by gc/ms. the oil yields were close to 0.1%, and the composition of the oils were somewhat different for each location. eighty-nine compounds were identified corresponding to about 95% of the oils. the main constituents of one of the oils were, methyl eugenol (29.5%), germacrene d (15.6%) and -caryophyllene (12.9%), whereas hexadecanoic acid (16.1%), phytol (10.6%), -caryophyllene (10.4%) and germacrene d (9.8%) were the main constituents in the other sample.