A comparative study of the position of the Venus nightside ionopause and of the orientation of the magnetic field in the near Venus wake is presented. It is shown that when the ionopause is detected deep within the umbra the magnetic field vector above that boundary shows consistently a convergent orientation toward the sun-Venus axis. When the ionopause is encountered outside the umbra, the magnetic field may assume directions not necessarily indicative of closure. The overall configurating of the nightside ionopause seems, in addition, to be strongly controlled by the kinetic energy density of the solar wind. At high values of this quantity the ionopuase tends to occur more often at low heights.