Two different grinding methods - rolling and hammer milling - as well as polyacrylate supplement in the diet were studied to evaluate their effect on the performance of pigs and the incidence of gastric lesions. The experiment was carried out in 2 x 2 factorial arrangement with a total of 160 pigs. The grist size of rolled barley was bigger than of hammermilled barley, but the difference in water-binding capacity was insignificant. No significant differences were observed in the performance traits of pigs fed either rolled or hammer-milled barley. The sodium polyacrylate supplement had no effect on the daily gain, feed:gain ratio or carcass quality of the pigs. Gastric ulcers and constrictions of the oesophageal opening of the stomach were more frequent in the groups fed hammer-milled barley than in the groups fed rolled barley, the difference being statistically significant (P<0.001). Sodium polyacrylate supplementation had no protecting effect against the incidence of gastric ulceration in growing finishing pigs.