The nutritional value of diets containing differently prepared barley was determined in two experiments. Barley grain was prepared in the following ways: hammer milled to medium fine (MH, 900 µm) or fine particles (FH, 600 µm), rolled (R), fine milled and expanded (E). Experiment 1 was conducted on 36 barrows, 28-95 kg BW (9 animals per treatment), fed individually using a ration system. Experiment 2 was carried out on 48 pigs (6 barrows and 6 gilts per treatment), 30-100 kg BW, maintained in groups and fed ad libitum. Daily weight gains, feed utilization and stomach lesions were determined in Experiments 1 and 2. In Experiment 1, nutrient and energy digestibilities were also assayed. It was found that the digestibility of protein (by 3.3 units), fat and energy (P<0.05) were better in the FH than in the MH diet and that the FH diet, and contained about 0.5 MJ/kg more metabolizable energy. The digestibility of diet R was also a slightly better (P>0.05) and contained more metabolizable energy than MH. The way of preparing barley had a greater effect on growth rate and feed utilization (P>0.05) in Experiment 2 in the pigs that were maintained in lots, fed ad libitum and gained about 900 g daily than in Experiment 1 in which pigs were fed rations according to standards and gained about 700 g. For the faster growing pigs, rolled and expanded barley had a somewhat greater nutritional value (daily gains 937 and 936 g), medium-fine milled barley had a lower value (865 g).