A learning organization refers to an ideal organization in which members continuously expand their capabilities to create outcomes they truly desire, nurture new and innovative thinking patterns, realize collective aspirations, and learn how to learn together with other members. However, Garvin et al. (2008) recently pointed out that despite the importance of learning organizations, many organizations still fail to become ideal learning organizations, and proposed a new diagnostic tool for evaluating learning organizations. The purposes of this study are, first, to evaluate learning organizations based on the new diagnostic tool proposed by Garvin et al. (2008), and second, to examine the relationships among learning organization, knowledge management activities, and work performance through a comparison of three models, given that numerous researchers have suggested a relationship between learning organizations and knowledge management activities. After securing the content validity of this study, a total of 271 questionnaires were analyzed using SPSS 14.0 and AMOS 5.0. The results showed that, first, a learning organization consisting of third-order factors was confirmed as a research model with second-order factors including learning process and practice, and leadership. Second, in the model comparison analysis, while the fit indices for the independent and mediation models generally met the recommended criteria, the main effect of knowledge management activities was found to be relatively weak in influence. When moderation effects were tested, the model fit improved beyond both the independent and mediation models, and the influence of the learning organization also improved accordingly. A discussion of the reasons behind these results was provided along with the implications and limitations of this study.