We conducted a descriptive analysis and meta-analysis of single-case research design (SCRD) studies investigating the effectiveness of the graduated guidance procedure. Once we identified studies through electronic databases and reference lists, we used What Works Clearinghouse (WWC) Standards to evaluate each study. Then, we described studies in terms of various descriptive variables, calculated effect sizes through three non-parametric effect size methods, and analyzed results across studies. Results showed 11 of the 27 studies met WWC Standards or met standards with reservation. Of the 11, seven studies resulted in a large effect. We found the graduated guidance procedure to be an evidence-based practice when evaluating the findings against contemporary evidence standards. However, this review also showed that the majority of the reviewed studies (n = 20) had no effects and only one third of the studies had moderate or strong effects. Implications for researchers and practitioners are discussed.