The interactions between two charged spheroids immersed in a symmetric electrolyte solution are evaluated. We show that the more closely two particles resemble spheres, the higher the electrical interaction energy between them. The variation in the total interaction energy between two particles, which includes the electrical and the van der Waals energies, reveals that the greater the radius of curvature of a particle, the higher the primary maximum or the harder it is for two particles to undergo an irreversible coagulation. If the double layer around a particle is thin compared with its radius of curvature, the critical coagulation concentration (CCC) of counterions is independent of the latter. This implies that the relative orientation between two particles is insignificant as far as the CCC is concerned. In this case, the result obtained in the present study reduces to that predicted by the Derjaguin-Landau-Verwey-Overbeek theory.