 The review discusses the use of acidic thermochemical pretreatment to facilitate enzymatic hydrolysis of cellulose in lignocellulosic feedstocks, which is typically followed by microbial fermentation. However, substances formed during pretreatment can inhibit both enzymatic hydrolysis and microbial fermentation steps. The review focuses on identifying inhibitors from lignocellulosic feedstocks and suggests methods to alleviate inhibition problems, such as chemical institute detoxification and improving the performance of bio-catalysts.