The present study aims at collecting and analyzing related researches on the effectiveness of metacognitive interventions in teaching-learning. The Flavell's metacognition model was taken as the theoretical framework of the study which includes knowledge of cognition in one hand and regulation of cognition in others. The review work was done in two phases, first the summary review is done to find out the metacognitive interventions used by the researchers in conducting field experiments. The summary review indicated brainstorming, self-assessment, concept mapping, and think aloud as metacognitive interventions used in different experimental studies. Secondly, related literature on the above-cited metacognitive interventions were collected and three studies for each metacognitive intervention were taken finally for meta-analysis with the help of Cohen d effect size. The results of meta-analysis revealed that the effect size for brainstorming was 0.733, 0.885, and 0.508 which reflected large effect and for concept mapping strategy 1.04, 0.97 and 2.38 which represented large effect size. On the other hand, one study for think-aloud strategy indicated 1.12 effect size which is having a large effect, and the remaining two studies indicated 0.443 and 0.24 which revealed a medium effect size. Finally, one of the effect sizes of self-assessment revealed a large effect, i.e. 1.2 and the rest two revealed medium effect i.e. 0.375 and 0.238. The study recommended promoting and encouraging brainstorming, concept mapping, think aloud and self-assessment in the teaching-learning process as the positive effect while large size effect was found in this process.