The aim of this experiment was to test the effect of herb - Origanum heracleoticum, herbs mixture - Origanum heracleoticum and Potentilla Erecta Raus and extract of Castanea sativa on growth and health condition of growing pigs. In parallel the effect of treatment of diarrhoea with antibiotics was compared with those of herbs mixture and concentrate of oregano oils. In total, 100 growing pigs after weaning took part in 2 trials, allocated to three groups in each trial. Herbs mixture did not affect positively food consumption, average daily gain and feed conversion ratio in growing pigs. Adding Origanum heracleoticum and Potentilla Erecta Raus into the food of pigs is an aid for the prevention of after weaning diarrhoea and for better welfare. It is necessary to continue the research with herbs and plant extracts as replacement of antibiotics searching for mechanisms of interaction of the active compounds of herbs in different doses and combinations.