During weaning, the outbreaks of diarrhea are quite common in piglets. During last decades, addition of antibiotics to the diets of weaning piglets was generally considered as a good way to reduce the occurrence of diarrhea because of its antimicrobial effect. A previous study demonstrated that dietary supplementation with 250 mg/kg grape-seed procyanidins had the potential to prevent weaning diarrhea by reducing intestinal permeability and improving antioxidant indices in rats (Song et al., 2011). Similarly, the results of the current study revealed that dietary addition of GSP ranging from 50 to 150 mg/kg could reduce diarrhea as effectively as antibiotics in weaned piglets. The current study indicated that GSP could be used instead of antibiotics in preventing the weaned pigs from diarrhea.