A study was conducted to determine the effect of dietary probiotic or antibiotics on growth, visceral weight, and intestinal and fecal unease activity in weanling pigs. Twenty-seven Landrace male pigs (7.2±0.4 ㎏) weaned at 24 d of age were divided into three groups of 9 pigs each on the basis of weight and litter. Three groups of three pigs (one pen) each were assigned to each of the following diets: a control diet or diets containing 0.1% probiotic (Bacillus toyoi spore) or 0.1% antibiotics (1:1 mixture of kitasamycin and sulfamethazine). Average daily gain (ADG), feed efficiency (G/F) and the visceral weight were measured, and unease activity in fecal samples (weekly) and intestinal contents (at the end of a 6-week feeding experiment) was determined. ADG and feed efficiency and relative visceral weight were not different (P$gt;0.05) among the three treatments. Unease activity in the stomach, small intestine and large intestine (cecum + colon) was not influenced (P$gt;0.45) by diets. Unease activity was much higher in the large intestinal contents than in the small intestinal contents. Fecal unease activity was lower (P$lt;0.01) in pigs fed the diet containing antibiotics than in pigs fed the control or the diet containing a probiotic. Results of our study suggest that the effect of dietary probiotics or antibiotics on unease activity and growth performance can vary, depending on animals and environments.