Kratom (Mitragyna speciosa Korth) leaves contain a major alkaloid, mitragynine, opioid pain-relieving activity. Kratom and its derivatives are abused as alternatives to other narcotics. Therefore, this preliminary study was aimed to optimize the extraction of mitragynine from kratom. The study includes investigating the effect of extraction time and ultrasonication on yield and quality of extract (the content of mitragynine). The extraction was carried out sequentially at room temperature and treatment of ultrasonication before extraction, which followed the purification process. Ultrasound-assisted extraction increased mitragynine yield to 16.88%, compared to extraction without ultrasonication. The extract was purified by column chromatography and eluted with a mixture of n-hexane-ethyl acetate-25% ammonia with a ratio of 30:15:1 (v/v). Likewise, the highest mitragynine purity obtained was 86.46%.