Customers are becoming more concerned about sustainable products while making purchase decisions especially in fashion and textiles. Therefore, large fashion brands are focusing to integrate sustainability concepts, which includes environmental, social and economic aspects into their business strategy and management. Many of the earlier publications focused on large fashion brands and in developed countries. However, there have been limited empirical study to examine the challenges faced by small and medium-sized enterprises (SMEs) in fashion and textiles to apply sustainability concept for their marketing activities. This study investigated the sustainability marketing approaches adopted by the SMEs particularly the fashion boutiques in Vietnam. We found that the fashion boutiques encounter limitations in the sustainable resources such as material and people with adequate knowledge. Furthermore, Vietnamese customers prefer to purchase clothes that are beautiful and wearable; and do not care about the sustainable approaches during the cloth manufacturing. It was also found that the fashion boutiques faced many challenges compared to large fashion brands to get certification on 100% ethical products.Index Terms-Sustainable fashion, sustainable marketing, boutique fashion, small and medium sized enterprise.