The fruit of Laser trilobum (L.) Borkh. (Umbelliferae) is a lesser known spice with cumin-like aroma. The fruits are rich in essential oil with the main constituents beinglimonene (26.7–91.0%) and perillaldehyde (4.4–62.0%). The results of GC and GC/MS analysis of the oils obtained under different conditions are given, and the effect of processing conditions on the ratio of main constituents are discussed. © 1993 Allured Publishing Corp.