It is important for pupils to be aware of their strengths and limitations as learners.Metacognitive environment provides scope for this. The present study ,represents the significance of metacognitive strategies on learning Mathematics in Co-operative groups. The study has considered Self Questioning and IDEAL Strategies on Metacognition with Co-operative Learning Approach .The study was carried out by following Post-Test only Control Group design. The findings of the study reveals that Metacognitive Co-operative Learning Approach enhances Mathematics Achievement among Secondary School students.It has also revealed that the approach is significantly more effective to high achievers as well as low achievers than traditional method,but the effectiveness is significantly more on high achievers than low achievers.