Although the generation and propagation mechanisms for whistlers are fairly well understood, the location and extent of the lightning source region for the whistlers observed at a given station are currently unknown. The correlation of whistler observations against global lightning data allows an estimate of the size and position of the source region. For whistlers detected at Tihany, Hungary, an area of positive correlation with radius of ∼1000 km was found to be centered on the conjugate point. Although the maximal sample correlation coefficient was relatively low, r = 0.065, it has a high statistical significance, indicating that it is extremely improbable that the whistlers and lightning in this region are actually uncorrelated. Other smaller areas of positive correlation were found further afield in South America and the Maritime Continent. Lightning in the northern hemisphere displayed a negative correlation with whistlers at Tihany.