This study examines the value, knowledge and sustainable consumption behavior of fashion consumers. The study shows that universalism/harmony, security/benevolence, power, and tradition/faith have positive effects on buying/usage behavior; however, hedonism/wealth has a negative effect. Stimulation/self-direction and universalism/harmony positively influence boycott behavior; however, power has a negative influence. Universalism/harmony and politeness have positive impacts on care/disposing behavior. Consumer knowledge about fashion related environmental problems, labor practices, ethical issues and sustainable environment knowledge influence sustainable buying/usage behavior; in addition, knowledge about ethical issues and sustainable environmental problems positively influence boycott and care/disposing behavior. Moreover, there were significant differences in values, knowledge, and consumption behavior by age.