A simple parameterization has been developed to simulate global lightning distributions. Convective cloud top height is used as the variable in the parameterization, with different formulations for continental and marine thunderstorms. The parameterization has been validated using two lightning data sets: one global and one regional. In both cases the simulated lightning distributions and frequencies are in very good agreement with the observed lightning data. This parameterization could be used for global studies of lightning climatology; the Earth's electric circuit; in general circulation models for modeling global lightning activity, atmospheric NOx concentrations, and perhaps forest fire distributions for both the present and future climate; and, possibly, even as a short-term forecasting aid. ¿ American Geophysical Union 1992