This paper is aimed at determining if direct taxes in Nigeria are buoyant and have significant relationship with human capital development. To achieve this primary objective, time series data were sourced from the Federal Inland Revenue Services and the National Bureau of Statistics covering a period from 1980 to 2017. Since the data already exist and cannot be manipulated, the ex-post facto research design was found appropriate and thus adopted. Direct taxes were proxy by petroleum profit tax buoyancy and company income tax buoyancy while human development index was used as a surrogate for human capacity development. The result shows that petroleum profit and companies income taxes are inefficient and not buoyant as the buoyancy and elasticity coefficients are less than one (bt < 1). It also shows that a positive and but insignificant relationship exist between petroleum profit tax buoyancy and human capital development. Furthermore, the relationship between companies’ income tax buoyancy and human capital development is found to be positive and significant. Based on these outcomes it was recommended that to improve human capital development and buoyancy of petroleum profit tax, the mobilized tax should be efficiently utilized in providing quality education, healthcare services, and basic infrastructures to the people. To further improve company income tax buoyancy; there should be continuous and regular review of the Nigerian company income tax statutes and other tax related issues by government agencies. Such tax reviews should be systematic and in alignment with the current macroeconomic objectives of the government and international best practices that will engender foreign direct investment and create enabling environment for private businesses to thrive. Such tax reforms should be directed at blocking tax leakages especially in the black market economy and any known loopholes in the tax legislations.