This study was performed to investigate whether postnatal administration with aged garlic extract (AGE) and allicin influences performance and systemic development of piglets exposed to early weaning. Twenty-four male piglets were weaned from sows at the age of two days of life, divided into 4 weight-matched groups and kept under conditions of artificial sow for 6 days. The first group consisted of control animals, while piglets that were given AGE daily per os at the dosages of 1 ml and 2 ml/kg body weight, respectively belonged to the second and third group. The fourth group consisted of piglets administered orally with allicin at the dosage of 1.0 mg/kg body weight/day. At the age of 8 days of life all animals were sacrificed. Next to body weight gain and morphological properties of the gastrointestinal tract, the haematological examination was performed, and activity of lysozyme and ceruloplasmin as well as level of gamma-globulins were determined. The obtained results showed that AGE and allicin improved final body weight, morphological properties of intestine villi and non-specific defence mechanisms of pigs. All these results indicate that AGE and allicin induced beneficial effects on health status, performance and systemic development of piglets.