We conducted a systematic review and meta-analysis evaluating the relationship between menu calorie labeling and calories ordered or purchased in the PubMed, Web of Science, PolicyFile, and PAIS International databases through October 2013. Among 19 studies, menu calorie labeling was associated with a -18.13 kilocalorie reduction ordered per meal with significant heterogeneity across studies (95% confidence interval = -33.56, -2.70; P = .021; I(2) = 61.0%). However, among 6 controlled studies in restaurant settings, labeling was associated with a nonsignificant -7.63 kilocalorie reduction (95% confidence interval = -21.02, 5.76; P = .264; I(2) = 9.8%). Although current evidence does not support a significant impact on calories ordered, menu calorie labeling is a relatively low-cost education strategy that may lead consumers to purchase slightly fewer calories. These findings are limited by significant heterogeneity among nonrestaurant studies and few studies conducted in restaurant settings.