Several years of military misrule and mismanagement had weakened the economic management processes and institutions in Nigeria. There was no transparency and accountability in government (Public Sector) and private sectors and Nigeria became notorious for endemic corruption. The result was the inability of government to deliver services to the Nigeria public. Most private companies both in the oil and non-oil sector have constantly evade taxes and have collide with officials to evade custom duties and payment of taxes. In addition, widespread perpetration of economic and financial crimes like advance fee fraud (419), money laundering, cyber crime, banking fraud and endemic corruption have had severe negative consequences on Nigeria, including decreased direct foreign investment in the country. Consequently, the Economic and Financial Crimes Commission (EFCC) was established as one of the mechanisms for the prevention, investigation and prosecution of corrupt practices and economic and financial crimes in the public and the private sector. Finally, this research work is aimed at looking into the various contributions of the Economic and Financial Crimes Commission (EFCC) in promoting financial accountability and transparency. To achieve this aim five research questions were developed. The study adopted the survey research approach using the three study areas. The EFCC Lagos, EFCC Enugu and PHCN formed the population of the study. A sample size of 55 was choosing using Taro Yamane’s model while simple random techniques was used to select the sample. Data retrieved from 55 completed questionnaires were subsequently presented in tables while simple percentage were used to analyse and answer the research questions formulated to guide the research work. After the analysis of data, the hypotheses tested reviewed that the contributions of EFCC has effectively promoted financial accountability and transparency in Nigeria. Therefore, the researcher recommends the following: developing an intensified information technology, staff training, capacity building and health care fraud control.