Tapping-mode atomic force microscopy was used to study the radial deformability of a multiwalled carbon nanotube (MWCNT). By imaging the MWCNT under different tapping forces, we were able to demonstrate its remarkable reversible radial deformability (up to approximately 40%) and reveal internal discontinuities along its length. The values of the effective elastic modulus of several sections of the MWCNT in the radial direction were estimated with the Hertz model.