Textile industry is commonly use dyes in colouring process which become the major dye wastewater source that leads to serious pollution in the environment. The disposed dyes can lead to serious harm to the water users and life in the aquatic because of the dye properties. Hence, the dye adsorption by activated carbon prepared from foxtail palm fruit was studied. The objectives of this study were: 1) to prepare activated carbon from foxtail fruit palm and 2) to study the effect of contact time, adsorbent dosage and initial concentration of dye usage toward the efficiency of the prepared activated carbon. Nitric acid was used as activating agent in this experiment, with impregnation time of overnight and 500 °C of 2.5 hours carbonization. The adsorption capability of foxtail fruit palm activated carbon as activated carbon was determined with the use of a dye called methylene blue. The results showed that 5 g of activated carbon was used to reduce 97.1% of 2 mg/L methylene blue with 150 minutes contact time. This result aligns with the SEM result which indicated that the produce activated carbon is rich with well-developed and irregular size of pores ranging between 1.585 μm to 7.556 μm. This study indicates that activated carbon from foxtail palm fruits could be utilized as an alternative activated carbon to treat dye wastewater.