This study examines the impact of environmental and social costs on performance of Nigerian manufacturing companies. With the use of secondary data, sourced from ten (10) randomly selected firms' annual report and financial summary 2014. The study makes use of t-test of Spss version 20 for the analysis of collected data. Finding from the analysis shows that the sample companies environmental and social cost significantly affect Net profit margin, Earnings per share and Return on capital employed of manufacturing companies. The researchers recommended that government should ensure complete adherence of environmental laws by manufacturing companies in Nigeria.