β-Glucans were successfully extracted from different cereals (barley, de-starched barley and wheat bran) in a fixed-bed extractor using pressurized hot water (PHW) as solvent, in the range of 110–175°C, at 20bar. Results were evaluated in terms of extraction yield, molecular weight of the extracted β-glucans and products of hydrolysis.Extraction yield was maximized at 155°C, 20bar and 4g/min of PHW for the three raw materials. Under these conditions, almost 100% of the initial β-glucans were extracted after 105min of operation, and the molecular weight of the extracted β-glucans was much higher (up to 500kDa vs. 180kDa) compared with batch operation, revealing the feasibility of the use of fixed-bed extractors for the β-glucan extraction. Under these conditions no degradation products, such as HMF, were detected in the extract.Experimental results have revealed that the operation in fixed-bed is adequate for the extraction and fractionation of high molecular weight β-glucans in a single step operation.