The purpose of this study was to examine the differences of the information searches and purchasing behavior Korean men in their 20s and 30s, focusing on cosmetic involvement. Research methods consisted of qualitative and quantitative approaches. For the qualitative approach, in-depth interviews and participant observations were conducted to investigate male customers' cosmetic characteristics in information searches and purchasing behavior. Then, the study conducted a quantitative study methodology based on the questionnaires from the in-depth interviews, participant observations, and literature review. The study surveyed 340 Korean men in their 20s and 30s. The cosmetic involvement of the target group was classified into the amusing high-involvement group, the rational low-involvement group, and the obligatory high-involvement group. The results from this study indicated that the groups of male customers classified by cosmetic involvement showed statistically significant differences in terms of information searches and purchasing behaviors. Especially, the obligatory high-involvement group generally displayed high-involvement traits likewise the amusing highinvolvement, was more similar to the rational low-involvement group regarding cost effectiveness than the obligatory high-involvement group. Moreover, the classifications of men generally had different characteristics of cosmetic purchasing behavior and information searches than women. This study has a distinctive significance compared with other studies in discovering differences of cosmetic purchasing behaviors of Korean men in their 20s and 30s’ cosmetic involvement groups classified using qualitative and quantitative approaches.