A general theory, based on asymptotic expansions, for the electromagnetic scattering by rotationally symmetric bodies, whose boundary is considered as a shape perturbation of the sphere, is constructed in this work. The parametric expression of the arc that generates the body by rotation is asymptotically expanded applying Maclaurin series. Next, the fields are expressed in asymptotic expansions using the spherical vector wave functions (SVWFs). The boundary conditions are then satisfied and lead to infinite nonhomogeneous sets for the evaluation of the unknown expansion coefficients. Depending on the body of revolution (BoR), these sets are solved analytically, in asymptotic closed form, and finally the whole procedure enables a closed-form evaluation of the scattering quantities. An application of the general theory for the scattering by a body of revolution is presented.