We examined the effect of extracts of meju prepared with traditional and standardized methods on pancreatic lipase and the absorption of dietary lipid. Aqueous methanolic (80%, v/v) extracts of meju dose-dependently inhibited the activities of porcine pancreatic lipase. The plasma triglyceride levels in Imprinting Control Region mice after a single oral administration of lipid emulsion containing aqueous methanolic extracts from meju made by the standardized methods were lower than that of the group given a lipid emulsion containing the extracts of meju made by traditional methods. The inhibitory activity of the meju extract on dietary lipid digestion appears to be more closely associated with aglycone forms of phenolic compounds such as free isoflavones than with glycosides, since meju samples with higher total phenolic or free isoflavone content showed the stronger inhibition against pancreatic lipase. Furthermore, the data suggest that meju made using the standardized method, which contains higher levels of total isoflavones relative to traditionally prepared meju, could effectively suppress digestion of dietary lipids and therefore have the potential to help ameliorate hyperlipidemia and obesity.