Anti-Corruption and Compliance programmes in multinational companies have become a common standard. In order for these programmes to be effective, international guidelines and best practice provide that Top Management needs to demonstrate Tone from the Top. However, it remains unresolved what Tone from the Top implies in practice and how it influences the effectiveness of anti-corruption. This book explores theoretically and empirically, what Tone from the Top means and how it can influence decision making with respect to corruption. Data was obtained from Nigerian managers within the oil and gas industry when facing corruption in an experimental environment. An innovative research design, the Drill Bit Business Simulation, was applied which imitates the realities and corruption opportunities of the Nigerian oil and gas sector. Results show how Tone from the Top influences moral and social motivations, which in turn steer the decision of managers whether to engage in corruption. On the basis of these new insights on corrupt decision-making in companies and the influence of Tone from the Top, this book provides practical recommendations on how anti-corruption programmes can be designed to become more effective.