Gnetum gnemon L. (Melinjo) is popular in Indonesia as a source of nutrition. Its seeds contain trans-resveratrol, that has been shown to have multiple pharmacological activities. The application of ionic liquid 1-n-butyl-3-methylimidazolium as a selected solvent in the microwave assisted extraction (MAE) method was develop for extraction of trans-resveratrol from Melinjo seeds. Ionic liquids proposed as green solvent. MAE method has also been applied to extract tans-resveratrol from different plant samples with a high extraction yield value. The Box-Behnken design on four factors (concentration of ionic liquid, microwave power, time of extraction, and liquid:solid ratio) with response surface methodology were used to optimize extraction conditions for ionic liquid based MAE of trans-resveratrol content from Melinjo seeds. The trans-resveratrol in the extract was determined by thin layer chromatography (TLC)-densitometry and high liquid performance liquid chromatography (HPLC). This extraction technique was a rapid and suitable to apply.