The aim of the study was to determine the effects of the use of a complementary herbal mixture in the prevention of weaned piglets. The experiment was conducted on piglets weaned from their mothers on 21stday of age. Piglets, hybrids of the Polish Landrace breed and Pietrain breeds, were divided into the experimental group and the control group, each consisting of 5 litters. Feeding took place in the system “eat at will” with a mixture of dry and granular feed, which had been prepared on the farm on the basis of the farmers’ own raw materials and those from the purchase. Piglets had constant access to fresh water. The experimental group was given an additive, which was a herbal blend mixture in the amount of 1250 g per 1 t full-dose feed mix. The supplementation dose was to reduce the occurrence of diarrhea in weaned piglets or a total elimination of its occurrence. The experiment proceeded since the weaning of piglets and lasted 14 days, during which measurements and observations of piglets’ biological value were performed. The analysis included: the weight of piglets on theday of weaning from the mother, the weight of piglets on day 7 after weaning, the weight of piglets 14 days after weaning, growth in assessed daily intervals, observations of behaviour and possible disease symptoms occurring in groups. The obtained results indicate that the addition of additive herbal mixture had no impact on the occurrence of diarrhea but it positively influenced the healthy piglets through a slight stimulation of growth.