A lightning detector, consisting of 12 silicon photodiodes, each with a field of view of 700¿700 km on the earth, has been flown on a Defense Meteorological Satellite Program satellite. Peak amplitude of the lightning flash was digitized within a range of 16 discrete levels, and the largest amplitude observed within a 1-s sample interval was recorded. Approximately 10,000 lightning flashes were analyzed. The frequency of occurrence of peak lightning power within the range 108-1010 W has been obtained. The median power level was 1¿109W, and about 2% of the lightning flashes had peak power greater than 1010W. These data are compared to similar results from a ground-based experiment. Lightning flash rate per unit area of cloud cover in a strom complex was 4¿10-5s-1km-2. The long-term flash rate per unit surface area on the earth was 6¿10-8s-1km-2, but this value may be biased toward high rates by the method of selecting the data base.