N-doped porous carbon materials derived from eco-friendly, renewable and economical biomass resources have attracted interest for applications in supercapacitors due to their porous structures and physicochemical properties. However, controlling the pore structure remains difficult and there is a need to simplify the N-doping process. Herein, we report a porous self-templated N-doped carbon aerogel derived from banana flesh obtained through one-step carbonization followed by CO2 activation. The specific surface area and pore distribution of the carbon aerogels could be controlled by changing the CO2 activation time. A specific surface area and total pore volume of 1414.97 m(2) g(-1) and 0.746 cm(3) g(-1) were achieved. The results show that raw banana flesh provides the necessary N content, which only slightly decreased following activation from 3.25% to 2.25%. On the surface of the carbon aerogel we detected pyrrolic N and pyridinic N groups, which are known to contribute to pseudo-capacitance. Furthermore, the specific capacitance of the prepared carbon aerogel reached 178.9 F g(-1) at a current density of 1 A g(-1). The simple preparation method and excellent electrochemical performance show great potential for application of our porous self-templated N-doped carbon aerogel as an electrode in high performance supercapacitors.