Glycogen is a homogenous and multi-disperse polysaccharide that is present in many clinically significant bacteria, such as Escherichia coli, Vibrio cholera and Mycobacterium tuberculosis. Its structure and metabolism have been linked with environmental viability, intracellular growth, pathogenicity and transmission capacity. However, due to the harsh extraction conditions and also the inconsistent methods for structure characterisation, understanding of bacterial glycogen structure and its association with bacterial metabolism and physiology has been hindered. Herewe gave a concise overview of bacterial glycogen structure with a focus on its recently discovered higher level organisation, a particle. Standardised procedures for glycogen extraction and structure detection are also highlighted.