We investigated characteristics of school-based mental health screening using multiple-gating (MG) approaches through a systematic review of the literature and proportional meta-analyses of screening participation and risk identification. The main analyses included 38 studies conducted in the United States. Pooled estimates indicate that approximately 72% of eligible students participated in initial screening, with 82% of eligible students participating in a second assessment. Approximately 24% of students participating in initial screening were identified as at-risk for mental health difficulties, with 65% identified at-risk in a second assessment. Participation rate was significantly associated with the type of consent process used, with participation rates of 55% and 58% in initial screening and a second assessment, respectively, for studies with active consent processes, and participation rates of 90% and 96% in initial screening and a second assessment, respectively, for studies with passive consent processes. Implications for future research and practice are provided.