The influence of a probiotic additive and aromatic oils from medicinal and spicy plants on the basic production parameters and on the incidence of intestinal disorders of weaned pigs (weaning at the age of 30-32 days) was compared in two trials in a commercial pig fattening farm (Michalovce, Slovakia). In the first trial, an experimental (nex = 38) and a control group (nco = 32) were used. A commercial probiotic additive containing Enterococcus faecium M-74 (6 × 10 8 CFU/g) and IgY antibodies (920 mg/g dried activated egg matter) against pig Rotavirus and different strains of Escherichia coli (K88, K99, 987P, F18) were added to feed mixture of the experimental group from 30 th to 40 th day (12 × 10 8 CFU/g) and subsequently from 40 th to 50 th day (6 × 10 8 CFU/g) of age. The second trial was performed with three groups of pigs (nex1 = 28, nex2 = 24, nco = 28). Aromatic oils isolated from sage (Salvia officinalis L., Labiateae) or oregano (Origanum vulgare L., Lamiaceae) were added to feed mixtures of the 1 st (90 mL/100 kg) and 2 nd experimental group (35 mL/100 kg), respectively, from 32 th to 53 th day of age. A statisticaly non-significant decrease of the incidence of diarrhoeal diseases was observed in the experimental groups of both trials as follows