In contemporary society, the severity of social problems, such as environment pollution, is gradually raising people’s awareness towards sustainability (Gleim, Smith, Andrews, & Cronin, 2013). The fashion industry’s interest in sustainability is growing. However, consumers have neither sufficient knowledge or, nor faith in, sustainable fashion, and often question the reasons to pursue sustainability (Skov, 2009). The success of sustainable fashion depends on effective branding and marketing communications strategies designed to enhance consumers' knowledge, benefit and value perception. Providing consumers with the benefits of new products is an effective way of communicating (Lee & Colarelli O'Connor, 2003). Knowledge is an important variable affecting consumers ' perceived benefits (Haas & Hansen, 2007). Consumers’ values, attitude, and knowledge also affect their environment awareness and actions (Laroche, Bergeron, & Barbaro-Forleo, 2001). According to a previous study, environmental knowledge plays an important role in consumer behavior (Tilikidou, 2006). Consumers perceive various kinds of value according to their knowledge (Haas & Hansen, 2007; Hartmann & Apaolaza-Ibáñez, 2012). Therefore, it is crucial to create awareness of the effect of consumer behaviors on the environment (Cegarra-Navarro, Cordoba-Pachon, & Fernandez de Bobadilla, 2009). Many studies have highlighted the leading factors influencing sustainable behavior (Cervellon & Wernerfelt, 2012). However, there a dearth of research on how sustainable knowledge influences perceived benefit, perceived value and behavior Thus, the purpose of the present research is as follows: (1) to identify the effects of sustainable fashion knowledge on perceived benefit and perceived risk, (2) to investigate how perceived benefit and perceived risk influence perceived value, and (3) to investigate perceived value’s influence on purchase intention and knowledge sharing intention. Sustainable fashion education, nationality, and uncertainty avoidance, will have a moderating effects on relationships among sustainable fashion knowledge, perceived benefit, perceived risk, perceived value, purchase intention, and knowledge sharing intention. Four hundred fifty samples were collected to measure sustainable fashion knowledge, perceived benefit, perceived risk, perceived value, purchase intention, knowledge sharing intention, uncertainty avoidance, and demographic variables. Data analysis was performed using SPSS 18.0 for descriptive statistics and exploratory factor analysis, and AMOS 18.0 for confirmatory factor analysis (CFA), validity test and multiple group analysis on the results. A measurement model was then estimated by examining the results of the CFA. The main results of this research are as follows: (1) sustainable fashion knowledge has a positive influence on perceived benefit and perceived risk, (2) perceived benefit and perceived risk have a positive influence on perceived value, (3) perceived value has a positive influence on purchase intention and knowledge sharing intention, and (4) there was a difference in the relationship between variables according to the consumer groups (education, nationality, uncertainty avoidance tendency). This study is meaningful for taking an in-depth look at the influence of customers’ perceived value, based on their level of sustainable knowledge, on consumer behavior and on knowledge sharing related to sustainable fashion. In terms of practical applications, this study can provide in-depth and empirically-supported online education and a brand marketing strategies regarding an actual sustainable fashion brand.