The study deals with the effect of diets supplemented with a hop extract on growing pigs. Two levels of the extract (500 or 1000 mg/kg of diet) were used. Feeds either unsupplemented or supplemented with butylated hydroxytoluene were used as negative and positive controls. Totally 96 pigs weighing ca. 60 kg were allocated to 4 groups. They were fed individually with restricted feed amounts. Water was available ad libitum. Body weight gain, apparent digestibility of nutrients, carcass and meat quality were estimated and biochemical indices in the blood were analyzed. The herbal extract decreased digestibility of fat and its higher dose also lowered protein deposition and mean body weight gains. Both doses of the extract lowered liver and kidney weight. The extract also improved meat oxidative and colour stability, decreased its cholesterol content, and positively affected the fatty acids pattern. A higher dose of the extract resulted in a worse smell and taste of meat.