This study was implemented to assess the effect of Pinus koraiensis extract (PKE) compared with zinc oxide on growth performance, nutrient digestibility, blood profile, fecal bacterial count, and fecal gas emission of post-weaned pigs. This 6 wk experiment was divided into phase 1 (days 1–7), phase 2 (days 8–21), and phase 3 (days 22–42). A total of 150 crossbred weaning pigs (body weight; 10.14 ± 0.78 kg) were randomly sorted in five treatment diets (six replications per treatment; five pigs per pen) presented as CON, basal diet; ZnO, CON + 0.30% zinc oxide; PKE1, CON + 0.05% PKE; PKE2, CON + 0.10% PKE; and PKE3, CON + 0.15% PKE. Pinus koraiensis extract supplementation linearly reduced gain to feed ratio in all phases except phase 3. It also linearly increased average daily gain in the overall experiment compared with the CON group. The increasing level of PKE supplementation brought linear improvement in aspartate aminotransferase of blood profile. Escherichia coli bacterial count and NH₃ gas emission were decreased linearly by PKE supplementation in comparison to the CON diet. Though PKE supplementation did not show similar influence as ZnO, it showed beneficial results in weaning pigs’ growth, nutrient digestibility, fecal bacterial count, and reduction of fecal gas emission.