Electron-impact ionization of hydrogenic ions is investigated in classical nonideal plasmas. The projectile-target interaction potential in classical nonideal plasmas is represented by the pseudopotential model. Semiclassical trajectory method is applied to the path of the projectile electron in order to visualize the ionization probability as a function of the impact parameter. The semiclassical ionization probability decreases with increasing the collective effect. It is also found that the collective effect increases with increasing the projectile energy. (C) 2001 American Institute of Physics. [DOI: 10.1063/1.1324658].