We report on a systematic ground-based validation of DMSP-OLS night lights imagery to detect rural electrification in Vietnam. Based on an original survey of village-level units in Vietnam, this study compares nighttime light output from the U. S. Air Force Defense Meteorological Satellite Program's Operational Linescan System (DMSP-OLS) against ground-based survey data on electrical infrastructure and electricity use in 200 electrified villages. Monthly and annual composites record a one-point increase in brightness along DMSP-OLS's 63-point brightness scale for every 60-70 additional streetlights or 240-270 electrified homes. Using a time series of 90 nightly images, the data show a one-point increase in brightness for every 125-200 additional streetlights, or 550-700 additional electrified homes. The results highlight the potential to use night lights imagery to support efforts to connect the 1.2 billion people who lack electricity around the world.