Mulberry leaves have been used in oriental medicine for their anti-pyretic and anti-inflammatory benefits. However, their bitter taste and characteristic odor limit their use in food. Thus, mulberry leaves were fermented using three species of lactic acid bacteria prevalent in kimchi. MLp, MLm, and MLs were obtained by means of fermenting mulberry leaves, using Lactobacillus plantarum, Leuconostoc mesenteroides, and Lactobacilllus sakei. Their palatability and biochemical properties were measured to determine the feasibility of using each as a food ingredient. Overall acceptability of yoghurt supplemented with fermented mulberry leaves (MLp, MLm, or MLs) was greater than that for yoghurt supplemented with dried mulberry leaves, while fermentation produced no negative effect on yoghurt palatability. In addition, the total polyphenol levels and radical scavenging effects of mulberry leaf extracts increased with fermentation, but total flavonoid content was not significantly changed. One potentially detrimental effect of fermentation is that α- glucosidase inhibitory potency was slightly decreased, proportional to the decrease in the active component 1-deoxynojirimycin. Despite this minor loss, the improved flavor of fermented mulberry leaves, together with its other beneficial health effects, is expected to render them useful as a food ingredient without lowering the sensory appeal of their target foods.