Scanning transmission X-ray microscopy (STXM) has been used to probe the electronic structure of individual multiwall carbon nanotubes bychemical mapping at the nanoscale. Carbon 1s near-edge X-ray absorption fine structure (NEXAFS) spectra of individual structures are shownto be able to differentiate carbon nanotubes from onionlike carbon nanoparticles and to differentiate nanotubes synthesized by differentgrowth methods. Imaging of the very same region by both STXM and transmission electron microscopy is shown to be a very useful andcomplementary approach.