Through this review we would like to introduce clean and efficient method of most conventional Friedel-Craft acylation of phenols using Ionic liquid. This method has best results of acylated phenols in terms of quality and yields are concerned. The Friedel-Craft acylation is an everyday applicable industrial synthesis. Phenols are dihydric, trihydric as well as monohydric hydrocarbons used to undergo acylation. Acetyl chloride is best suitable reagent for aromatic C-acylation. Ionic liquid [EMIM][AlCl4] has best solvation and catalytic effect in the reaction. Key Word: Friedel-Craft Acylation, Phenols, Ionic liquid [EMIM][AlCl4], Acetyl Chloride