The isolation of cellulosic fibers and their applications in composite materials have drawn considerable interest due to their outstanding thermal and mechanical properties combined with light-weight character, biodegradability, and renewability. Bamboo is a fast-growing plant, and its properties include sustainability and excellent tensile strength. In this study, bamboo fibers from the culms and shoots of Dendrocalamus asper were treated with 5 wt% sodium hydroxide and subjected to ultra-sonication for 5 hours to obtain bamboo cellulose. Infra-red spectra showed that lignin and hemicelluloses were removed after treatment. With the removal of amorphous cellulosic regions, both cellulosic fibers exhibited higher decomposition temperatures than the raw fibers. Thermogravimetric analysis confirmed that both types of bamboo cellulose had a peak decomposition temperature at 408 °C. Cellulose isolated from the bamboo shoots exhibited similar chemical and thermal properties, indicating its huge potential as an alternative to mature bamboo culms.