An effective procedure for fat determination in animal feed samples according to COMMISSION REGULATION (EC) No 152/2009 is presented. The sample is hydrolyzed prior the extraction. The Twisselmann extraction is performed with the Extraction Unit E-816 ECE (Economic Continuous Extraction).This allows the sample to be constantly kept in hot solvent vapor whilst efficiently rinsed with freshly distilled solvent. After the extract has been dried to a constant weight the total fat content is determined gravimetrically. The reference value was determined using Soxhlet extraction.