This study is to ascertain the effect of human capital expenditures on corporate social responsibility of oil and gas firms in Nigeria It spanned for the period of 10 years (2008-2017) and made use of secondary data extracted from the financial reports and accounts of the oil and gas firms selected for the period. The study adopted ex-post facto research design and employed the panel least squares multiple regression analysis. Findings of the study provided empirical evidence that human capital expenditures proxy by expenditure on salaries and wages, on education and training and expenditure on health have significant positive effect on Corporate Social Responsibility (CSR) of oil and gas firms in Nigeria. This implies that increases in volume of corporate social functions of the firms are associated with increases in spending on the human capital indices. Based on these findings, it was recommended among others that oil and gas firms should keep up in the corporate supports to the community since it helps in the growth of their firms and ensure good salary pay structure for their workers to motivate them in community supports.