This study examined the effect of public spending on economic development in Nigeria from 1980 to 2020. The study was induced by the insufficient and fluctuatory federal government budgetary allocations to some critical sectors such as agricultural, education and construction sectors that tend to prompt the existence of deteriorate academic and food production, as well as infrastructural decay amongst others. Thus, the specific objectives of the study were to; examine the impact of total government spending in agricultural, education and construction sectors on economic development in Nigeria. In doing this time series were collected from CBN bulletin from 1980-2020. The unit root test, Johansen cointegraton test and Error Correction Mechanism were employed for the analysis. The ADF unit root, Johansen cointegraton test showed that all the variables were stationary and have long run relationship respectively. The results of the parsimonious error correction model showed that, total government spending in the agricultural, education and construction sectors have positive relationship with economic development. In conclusion, government fiscal activity via public spending is crucial to achieving economic development in Nigeria. Based on the findings, the study recommended amongst others that, government should increase her spending in viable infrastructure in order to increase the level of growth and development in the Nigerian economy.