Bacterial cellulose (BC), which is produced by bacteria, has unique and desirable structural, physical and chemical properties. The production process and intrinsic properties of BC have been widely investigated. Recently, these studies have focused on functionalized BC materials and BC-based composites, where BC is used as a substrate. Following this trend, this paper provides general information about cellulose as well as BC cultivation and its properties. The recent advances in BC modification methods and the properties of current BC-based composites are also emphatically reviewed. The potential for further BC work is also examined.