Abstract: Human capital investment has been seen as impetus to sustainable economic growth and this has necessitated the increase in government spending by major economies including Nigeria in order to achieve a steady long-run growth path and meet up with the Millenium development goal target. On this basis, the effect of human capital investment on economic growth in Nigeria between a decade after independence (1970) and 2009 is examined based on the endogenous growth theory framework. Following the underlying assumptions of the Endogenous Growth Model, real output is regressed on private capital investment, government human capital investment, human capital consumption and openness to trade. The time series of the variables were examined using the Augmented Dickey-Fuller unit root test and all of the series were found non-stationary at levels excluding population growth of economic active. Engle-Granger Cointegration test result revealed that there is long-run growth path between human capital investment and economic growth in Nigeria. However, the result of the cointegrating regression indicated that capital investment from the private and public sector and human capital consumption tends to be important factors that enhance real economic growth in Nigeria. While growth of economic active population and economic openness exert negative influence on economic growth in Nigeria.