A substantial night side ionosphere has been observed on Venus by both Mariner 5 and Mariner 10. Major dayside ionic species such as O2 + and other molecular ions have chemical lifetimes much shorter than the 244.3-day rotation period of the planet. Rapid transport of ions from the day side to the night side to the extent required seems most unlikely. Consequently, we have investigated possibilities for local production of ions on the night side itself. Constraints imposed by chemical lifetimes require atomic ions with low ionization potentials. We suggest that metallic ions of meteoric origin are the positive charge carriers and demonstrate the plausibility of this mechanism. Other possibilities are examined and shown to be less likely. Meteor ablation on Venus, the aeronomy of metallic species, and the role of negative ions near the electron peaks of the atmosphere are discussed.