A systematic review was performed to evaluate the efficacy of silver diamine fluoride (SDF) in controlling caries progression in children when compared with active treatments or placebos. A search for randomized clinical trials that evaluate the effectiveness of SDF for caries control in children compared to active treatments or placebos with follow-ups longer than 6 months was performed in PubMed, Scopus, Web of Science, LILACS, BBO, Cochrane Library, and grey literature. The risk of bias tool from the Cochrane Collaboration was used for quality assessment of the studies. The quality of the evidence was evaluated using the GRADE approach. Meta-analysis was performed on studies considered at low risk of bias. A total of 5,980 articles were identified. Eleven remained in the qualitative synthesis. Five studies were at “low,” 2 at “unclear,” and 4 studies at “high” risk of bias in the key domains. The studies from which the information could be extracted were included for meta-analysis. The arrestment of caries at 12 months promoted by SDF was 66% higher (95% CI 41-91%; p < 0.00001) than by other active material, but it was 154% higher (95% CI 67-85%; p < 0.00001) than by placebos. Overall, the caries arrestment was 89% higher (95% CI 49-138%; p < 0.00001) than using active materials/placebo. No heterogeneity was detected. The evidence was graded as high quality. The use of SDF is 89% more effective in controlling/arresting caries than other treatments or placebos. The quality of the evidence was graded as high.