This paper investigated the outcome of the adoption and implementation of Medium-term Expenditure Framework (MTEF) in the Nigeria budgeting process. MTEF is eulogized by the World Bank, and even donor organization DFR as the panacea to the poor public expenditure management (PEM) prevalent in most of sub – Sahara African Countries. MTEF was first adopted in Nigeria, following the passage of the Fiscal Responsibility Act 2007 Act 30 to guide her national annual budgeting process. Using simply statistical methods, we collated data from sixteen national budgets (2003 - 2016), and constructed statistical tables to investigate the MTEF in the Nigeria annual budgets. Using correlation coefficient, we examined the behaviour of three key fiscal and expenditure items in Nigeria annual budgets.Our findings showed strong positive correlation between the budgeted and actual figures in all three fiscal items. Oil production was negatively corrected with the actual. We concluded, following our findings that the adoption and implementation of MTEF has to a large degree improved fiscal discipline in the Nigeria budgeting process.