Despite the growing interest of environmentally friendly clothing (EFC), there have been discrepancies among customers in defining EFC. The purposes of this study were to assess the participants’ environmental orientation and environmental knowledge toward EFC, to compare them in terms of college major and gender and identify relationships between orientation and knowledge, and to acquire the current perceptions and practices toward EFC. The revised New Environmental Paradigm scale (NEP) with 15 items, the Environmental Apparel Knowledge scale (EAK) with 11 items, and the developed perception and practice question sets with 12 items were used. A total of 122 undergraduate students participated through an online survey. Results indicated that students in sustainability-related majors have higher ratings in knowledge than students in other majors. Gender was not found to make a significant difference in either orientation or knowledge ratings. Orientation and knowledge were positively correlated, but not strongly. Results present the need for reinforcement of sustainable contents in university curricula. Practical feedback from this study has the potential to assist with the development of effective marketing campaigns. Sample size and grouping of majors are possible limitations in this study.