While corporate social responsibility (CSR) has been extensively explored from the standpoint of large corporations and developed economies, smaller businesses and developing economies have received little attention. Small and medium-sized enterprises (SMEs) continue to be the backbone of most economies, significantly accounting for a major share in economic value creation. This implies that the contribution of SMEs in achieving sustainable development is therefore critical. The study seeks to add to the limited literature by investigating the implication of socially responsible behavior on the performance of SMEs in Nigeria. Corporate reputation, profit maximization and management efficiency are dependent variables used as proxies for performance measurement. A well-structured questionnaire was administered to 63 Nigerian SMEs. The study adopted a structural equation model using SmartPLS for the data analysis. Findings show a significant relationship between corporate social responsibility and the three determinants of firm performance (management efficiency, profit maximization and corporate reputation). This study has implications for owners/managers of SMEs who are keen on improving performance by leveraging on socially responsible behaviour through the development, implementation and communication of a sustainable and acceptable CSR initiative. Recommendations and suggestions for further investigations are made.