Economic diversification has been the glamour of successive administrations in Nigeria, especially amidst the dwindling oil-revenue in recent years, which has resulted from the fluctuations in world crude oil prices. This study aims at investigating the impact of diversifying the economy on the economic growth in Nigeria. Secondary data on GDP growth rate as a proxy for economic growth, non-oil GDP as a proxy for GDP diversification, non-oil export as a proxy for export diversification, investment and exchange rate, between 1981 and 2016, were adopted in the study. An econometric approach of Ordinary Least Squares (OLS) was adopted to empirically analyze the collected data and the result revealed that non-oil gross domestic product impacted positively and significantly on economic growth while exchange rate had an inverse but significant nexus on economic growth in Nigeria, within the period covered in the study. However, non-oil export and investment impacted positively but insignificantly on economic growth in Nigeria. The study recommends the encouragement of increased productivity in the real sector as well as the adoption of stable and favourable exchange rate policies by the government in order to accelerate economic growth in Nigeria.