Mitragyna speciosa is a narcotic plant but with specific medicinal importance. The main components of the leaves of M. speciosa are indole alkaloids. Previous scientific researches have shown that the alkaloidal extracts possess very potent anti-inflammatory, analgesic and opioid properties. The three most abundant indoles are mitragynine, paynanthine and speciogynine, the first two of which appear to be unique to this species. All these compounds were obtained from classical organic solvent (ethyl acetate, dichloromethane or methanol) extraction. CO2 extract of M. speciosa has never been studied yet. Hence, in this present investigation, supercritical fluid extraction (SFE) of M. speciosa was performed. Comparison of the TLC of SFE extracts with that of the ethyl acetate extract from this preliminary study shows no alkaloid was extracted out with 100% CO2. Alkaloids were only extracted with eluent system using ethanol as co-solvent and the optimal conditions was CO2-ethanol (80% EtOH), 40 °C and 5000psi. CO2 was chosen as the media of extraction because it is non-toxic and environmentally safe to prepare and use.