This cumulative meta-analysis examined the predictive validity of actuarial risk measures (RRASOR, Static-99, Static-99R) with developmentally delayed sexual offenders. In Study 1, a meta-analytic average was calculated from four studies using the RRASOR or Static-99. Based on a fixed-effect model, both measures were significantly related to the risk of sexual recidivism. Study 2 examined five actuarial risk measures (RRASOR, Static-99, Static-99R, Static-2002, Static-2002R) with 52 developmentally delayed sex offenders, finding good predictive accuracy for all measures (0.80 < d < 1.15). When the effect sizes from all previous findings were combined in Study 3, the average effect size for the RRASOR was moderate (d = 0.56, 95% CI of 0.08 to 1.04, k = 4, N = 280) and large for the Static-99R (d = 1.04, 95% CI of 0.39 to 1.69, k = 2, N = 66) and Static-99 (d = 0.77, 95% CI of 0.45 to 1.09, k = 4, N = 160). Given the consistency of the current results with the findings with non-DD sexual offenders, we recommend the use of the Static-99/R and Static-2002/R with developmentally delayed sexual offenders.