Available literature has shown that the impact of total government expenditure as well as government expenditure by type of economic growth is mixed. This study extends this literature by examining the impact of government expenditure on agriculture, on Nigeria's economy from 1970 to 2006. General-to-specific methodology of time series econometrics was utilised to arrive at the preferred error correction model that was used to determine the impact of government spending on agriculture and on economic growth. In consonance with economic theory, the results showed that the total expenditure on agriculture had a positive significant effect on Nigeria's economic growth in the long run with elasticity of 0.32 during the period under review. The results also showed that economic growth was independent of recurrent expenditure, but dependent (positively) on capital expenditure in the long run with elasticity of 0.36. The implication is that agriculture should be given priority in budgetary allocation and capital spending to promote economic growth in Nigeria.