Corruption is a multidimensional phenomenon difficult to measure. Finding the methods for effectively measuring the extent of corruption has been the subject of much attention and many studies among scholars and professionals. Despite the fact that accurately assessing corruption is inherently impractical, there is a consensus that measuring corruption is nonetheless conceivable. The existing measurement approaches can be mainly categorized into two groups: fact-based (objective) measurements and perception-based (subjective measurements). This paper addresses the doubts as to whether and to what extent these approaches are able to provide a valid and reliable picture of corruption.