A nanosized carbonaceous material was derived from bacterial cellulose (BC). BC, which is produced by bacteria as nanosized material, possesses high degree of crystallinity of 90 %, was pyrolysed at 950 A degrees C and physically activated with CO2 to produce a nanosized activated carbon material. The pyrolysis of BC yielded a carbonaceous material (carbon yield of between 2 and 20 %) with a relatively low D- to G-band ratio (between 2.2 and 2.8), indicating that the carbonaceous material possesses a graphitic structure. Two different BC materials were pyrolysed-a loose fibrous (freeze-dried) and dense paper form. It was observed that a carbon nanofibre-like material was produced by the pyrolysis of the loose fibrous form of BC. The electric double layer (EDL) capacitance and the area-normalised specific capacitance in K2SO4 solution were as high as 42 F g(-1) and 1,617 F cm(-2), respectively. The EDL capacitance was also compared to commercially available activated carbon (YP-50F).