A shifted -l expansion technique is introduced to calculate the energy eigenvalues for Klein -Gordon (KG) equation with Lorentz vector and/or Lorentz scalar potentials. Although it applies to any spherically symmetric potential, those that include Coulomb -like terms are only considered. Exact eigenvalues for a Lorentz vector or a Lorentz scalar, and an equally mixed Lorentz vector and Lorentz scalar Coulombic potentials are reproduced. Highly accurate and rapidly converging ground -state energies for Lorentz vector Coulomb with a Lorentz vector or a Lorentz scalar linear potential, V (r) = −A 1 /r + kr, and V (r) = −A 1 /r and S(r) = kr, respectively, are obtained. Moreover, a simple straightforward closed -form solution for a KGparticle in Coulombic Lorentz vector and Lorentz scalar potentials is presented in appendix A.