The aim of this study is to better understand why public officials and business employees engage in corruption. Insight into individual-level explanations for corruption was obtained with the aid of a self-report survey. The results suggest that the most indicative factors of whether or not individuals are corruption-prone are as follows: the moral conviction they have to refrain from corruption; perceptions of whether their colleagues approve of and engage in corruption; and difficulties experienced in complying with the rules on corruption. This result pattern was identical for public officials and business employees alike, and as a consequence, for both sides of corrupt acts. The latter indicates that the same motives may not only underlie corruption in both private and public sectors, but also the act of corruption in its active and passive forms. The results of the current study do not provide strong support for the assumption that economic considerations—expected costs and benefits—are crucial in predicting corruption. Based on the findings that norms and the perceived opportunity to comply are dominant factors in explaining corruption, this article focuses on the practical implications for the development of anti-corruption strategies within both public and private sectors.