In recent years, people have been increasingly motivated by ethical consumption and accordingly, products featuring environmental claims have obtained unprecedented popularity in various retail sectors. The apparel industry is no exception, offering a variety of environmentally friendly products to satisfy the preferences of socially responsible consumers. Among these, one of the most representative and popular products could be apparel made with organic cotton which is grown under sustainable farming practices (Lin, 2010). However, it is reported that familiarity with organic cotton is considerably low among consumers (Ha- Brookshire & Norum, 2012). This could be problematic, especially to organic cotton product retailers, because familiarity or perceived knowledge is an essential factor in consumers’ decision-making process (Alba & Hutchinson, 1987). In order to provide a clear overview about the influence of product familiarity on consumers, this study developed a typology of consumers based on familiarity level with organic cotton and identified differences among subgroups in their purchase behavior.