This study examining the impact of foreign direct investment (FDI) and other macroeconomic variables on agricultural growth in Nigeria from 1981 to 2014, using annual time series data from Central Bank of Nigeria (CBN), World Bank and the United States of America (US) Federal Reserve System. Data was analysed using trend analyses, unit root tests, co-integration tests, ordinary least squares (OLS) regression and Granger causality tests, while the hypothesis was tested with F-test. Results revealed very low FDI inflow into agriculture, not commensurate with the share of agriculture to GDP. All significance were taken at the 5% probability level, i.e. p<0.05. There was positive non-significant relationship between agricultural growth and FDI in agriculture, meaning that FDI in agriculture has no direct impact on agricultural growth or the impact on agricultural growth is masked by other macroeconomic variables. Significant positive relationship exists between agricultural growth and macroeconomic instability, while interest rate differential had a significant negative relationship. There was unidirectional causality running from FDI in agriculture, stock of gross external debts, and variability of consumers’ price index to agricultural growth, while agricultural growth was significant in granger causing macroeconomic instability. Recommendations are government should not involve itself in business, but seek for and encourage more FDI for the agricultural sector, encourage joint ventures between foreign and domestic investors/entrepreneurs, ensure stability and consistency in its macroeconomic policies, while monetary policy rates should be fixed in such a way that it would attract the right amount of investments in agriculture.