This review article discusses the chemical and physicochemical pretreatment of lignocellulosic biomass to enhance its digestibility for biofuel production. Lignocellulosic biomass, composed of cellulose, hemicellulose, and lignin, is resistant to enzymatic hydrolysis due to its crystalline structure and the presence of lignin. Pretreatment aims to break down these structures, increase cellulose accessibility, and improve sugar yields for fermentation. Pretreatment methods include physical, chemical, physicochemical, and biological approaches. Chemical pretreatments such as alkaline, wet oxidation, acid, and green solvents (like ionic liquids and NMMO) are effective in breaking down lignin and hemicellulose, increasing cellulose accessibility, and reducing enzyme loading. Physicochemical methods like steam explosion and ammonia fiber explosion (AFEX) also disrupt biomass structures, improving enzyme access and sugar yields. Each pretreatment has advantages and disadvantages, with considerations for cost, efficiency, and environmental impact. The review highlights the importance of pretreatment in reducing costs and improving the economic viability of biofuel production, emphasizing the need for further research to optimize these processes for large-scale application.This review article discusses the chemical and physicochemical pretreatment of lignocellulosic biomass to enhance its digestibility for biofuel production. Lignocellulosic biomass, composed of cellulose, hemicellulose, and lignin, is resistant to enzymatic hydrolysis due to its crystalline structure and the presence of lignin. Pretreatment aims to break down these structures, increase cellulose accessibility, and improve sugar yields for fermentation. Pretreatment methods include physical, chemical, physicochemical, and biological approaches. Chemical pretreatments such as alkaline, wet oxidation, acid, and green solvents (like ionic liquids and NMMO) are effective in breaking down lignin and hemicellulose, increasing cellulose accessibility, and reducing enzyme loading. Physicochemical methods like steam explosion and ammonia fiber explosion (AFEX) also disrupt biomass structures, improving enzyme access and sugar yields. Each pretreatment has advantages and disadvantages, with considerations for cost, efficiency, and environmental impact. The review highlights the importance of pretreatment in reducing costs and improving the economic viability of biofuel production, emphasizing the need for further research to optimize these processes for large-scale application.