3-dimensional lightning mapping observations obtained in central Oklahoma by the New Mexico Tech Lightning Mapping Array (LMA) have been compared with optical observations of the discharges from space obtained by NASA's Lightning Imaging Sensor (LIS). Excellent spatial and temporal correlations were obtained between the two sets of observations. All lightning discharges seen by LIS were mapped by the LMA. Most of the detected optical events were associated with lightning channels that extended into the upper part of the storm. Cloud-to-ground discharges that were confined to mid- and lower-altitudes were less well detected than intracloud discharges, and tended to be detected late in the discharge. Intracloud discharges were readily detected by LIS as soon as they extended into the upper part of the storm, and often extensively illuminated the cloud at the end or part way through the discharge. The extensive illumination was impulsive in nature and was also seen at the end of some cloud-to-ground discharges. ¿ 2000 American Geophysical Union