Recently, there is a resurgence of interest in using plants as a sole source of food and medicine. According to Elless et al. (2000), plants are known to be abundant sources of bioactive phytochemicals and antioxidant nutrients. It is now widely accepted that some classes of compounds of plant origin such as dietary fibers, phenolic acids, flavonoids, vitamins and antimicrobial agents and neuropharmacological agents play a preventive role against diseases such as cancer, cardiovascular and neurodegenerative disorders (Siddhuraju and Becker, 2007) . . In recent decades, scientific evidence of the pharmacological and nutraceutical activities of medicinal herbs such as antioxidant, anti-tumor and anti-inflammatory activities has been established (Edris et al., 2007). Ndukwe et al. (2005) noted that scientists' efforts in creating plants with promising antimicrobial activity were yielding fruitful results. Plants are available and cheaper than conventional drugs (Owhe-Ureghe et al., 2010). One of these plants is Citrus aurantifolia (lime) which is the second most important citrus fruit for both fresh consumption and industrial uses and is the fifth largest crop in terms of harvested area worldwide (Pourmartazavi and Hajimirsadeghi, 2007) . Jones (1995) stated that C. aurantifolia belongs to the Rutaceae family which includes 160 genera and 1650 species. C. aurantifolia is a polyembryonic species with a smooth fruit surface, greenish-yellowish in color and thin peel, solid core when ripe and strongly acidic with a pleasant smell. It is now found primarily in warm subtropical and tropical regions such as southern Florida in the United States, India, Mexico, Egypt, and the West Indies (Morton, 1987). aurantifolia is also popular in the midst of an article dealing with better methods for extracting C. aurantifolia essential oil and research into related issues such as antimicrobial activities. Besides that, it serves as a comparative purpose where the oil is compared with others for quality control or investigation for adulteration, to discover new components or to characterize the classes of components found.1.4 Objectives of the StudyThe objectives of this research are: I. Extract essential oil from C. aurantifolia fruits by hydrodistillation and steam distillation methods.II. Compare the yield and percentage composition of essential oil in C.aurantifolia fruits using hydrodistillation and steam distillation methods.III. Analyze and determine the chemical constituents of C.aurantifolia essential oil by gas chromatography-mass spectrometry.