Context:Syzygium polyanthum has been traditionally formulated by the folklore for the treatment of diseases including diarrhea, rheumatism, diabetes mellitus, hypercholesterolemia, hypertension, gastritis and hyperuricemia. Normally, its phytochemicals are always extracted using solvent, maceration and steam distillation methods, but the use of ultrasound-assisted extraction (UAE) method is still not well documented. Aims: This study aims to extract the phytochemical compounds present in S. polyanthum leaves using UAE and to identify them by Gas Chromatography-Mass Spectrometry (GC-MS) analysis. Methodology: The leaves were consecutively soaked with n-hexane, ethyl acetate and methanol in a bath sonicator to derive n-hexane (HSP), ethyl acetate (EASP), and methanol (MSP) extracts of S. polyanthum leaves and then the extracts were subjected to GC-MS analysis. Mass-spectral databases of peaks were compared with database from Wiley, NIST and FNSCC libraries for compound identification. Results: GC-MS analyses of HSP, EASP and MSP showed the presence of 21, 27, and 31 peaks, respectively. The major compound for HSP (31.912%), EASP (27.042%), and MSP (22.386%) were unknown compounds which were detected at retention time between 61.980 and 62.29 min, thus requires further characterization. Squalene and phytol were among the other major compounds present in all three extracts. Several identified compounds in the extracts such as squalene, phytol, hentriacontane, palmitic acid, α-pinene, nerolidol, linalool, α-tocopherol and β-tocopherol were known bioactive compounds. analysis of crude methanolic S. polyanthum leaves extract showed the presence of tannins, flavonoids, glycosides, alkaloids, carbohydrates, steroids, triterpenoids and flavonoids. 5,6 Phenolic compounds such as caffeic acid and gallic acid were previously identified in crude macerated methanolic extract of S. polyanthum leaves by high performance liquid chromatography and liquid chromatography mass spectrometry analyses. Conclusion: GC-MS analyses of n-hexane (HSP), ethyl acetate (EASP),7 Analysis on the crude macerated methanolic extract of S. polyanthum leaves has detected squalene as the major compound. 5,8 Another analysis on the macerated n-hexane extract similarly found squalene as the major compound (30.45%) followed by n-hentriacontane (6.57%). 8Most phytochemicals previously studied were extracted using solvent maceration and steam distillation methods, however, the use of ultrasound-assisted extraction (UAE) method is not well-documented. The present study has utilized UAE method, a different extraction method from the other previous studies. Basically, UAE method Rahim et al.: GC-MS Analysis of Syzygium polyanthum Leaves Extracted using Ultrasound-Assisted Extraction MethodPharmacognosy Journal, Vol 10, Issue 1, Jan-Feb, 2018 111 GC conditionThe injector temperature was set at 250 º C, column temperature program was set at 50ºC (0 min) with an increasing rate of 3 º C/min to 300 º C (10 min). The carrier gas used was pure helium gas (9...