This paper examines whether socially responsible investment (SRI) outperforms conventional investments by meta-analysis. The result shows that weighted average effect size is not significantly different from zero, suggesting that SRI performance is not different from conventional investments. Meta-regression results regarding sampling issues indicate that economic crisis, control group, investment universe, screening procedure, and mutual funds are important determinants of effect sizes, and publication year, author type, and control group are important factors of the absolute value of effect sizes. Regarding methodological issues, risk adjustment, weighting scheme, data refinement, benchmark model, and matching procedure are significant factors determining the absolute value of effect sizes.