The objective of this study was to evaluate the antioxidant activity of yuza chocolate,and to determine the optimum ratio of yuza powder for its preparation. Yuza peel and flesh powders were added to chocolate at weight percentages of 0, 3, and 6%, respectively. Color values (L-value, redness, and yellowness), total phenol content, total antioxidant capacity, DPPH radical scavenging activity, and sensory characteristics were then measured in the samples of yuza-containing chocolate. As the amount of yuza powder increased, total phenol content, antioxidant capacity, and radical scavenging activity increased. Depending on the level of yuza powder, significant differences (p <0.05) were shown in aroma, taste, bitterness, and overall acceptability however, there were no significant differences in texture. In terms of sensory acceptability, the addition of 3% yuza peel powder to chocolate was optimal.