We test whether Corporate Social Responsibility (CSR) is driven by strategic considerations by empirically studying the link between competition and firms’ social performance. We find that firms in more competitive industries have better social ratings. In particular, we show that (i) different market concentration proxies are negatively related to widely used CSR measures; (ii) that an increase in competition due to higher import penetration leads to superior CSR performance; (iii) that firms in more competitive environments have a superior environmental performance, measured by firm pollution levels; and (iv) that more product competition is associated to a larger within-industry CSR variance. We interpret these results as evidence that CSR is strategically chosen.