This assessment seeks to understand the wide-reaching impact of maritime corruption on the industry and society. Using Nigeria as a case study, the study reveals how direct and indirect costs of corruption in the maritime sector is driving up the total transport and logistics costs for the industry by 15%, resulting in annual cost of corruption ofover USD 162 million for the industry. This is a significant cost borne by the private sector and that has severe knock-on effects further down in the supply chain and ultimately impacts the end consumer. The findings demonstrate a clear economic benefit and a compelling business case for proactive anti-corruption measures by both governments and businesses. These benefits have positive ripple effects for the entire economy, domestic revenue mobilisation, the business climate, and people’s livelihoods.