The economic recession that ravaged many nations including Nigeria has opened the eyes of leaders, academicians and researchers in search for what can be done in order to reduce its negative effects on citizens. It is in this regard, that this work examined the relationship between economic diversification activities and national income measured by GDP. This work would help Federal Governments, States and Local Governments leaders and partners to diversify economic activities with main aim of maximizing national income measured through GDP. It would help researchers to have current evidence about the contribution of diversification of economy in improving national income of a nation, which is source of funds that support public expenditure measured by physical and social infrastructures that improve quality of life of citizens. The results demonstrated that agriculture is imperative, food and beverages play a vital role and mining sector is still undeveloped in Nigeria. The work concludes that diversification in a fundamental option that will solve national challenge and it recommends for diversification in many sectors than only relying on crude oil.