: The objective of this study is to assess the effectiveness of mathematics learning model through metacognitive-based learning. The assessment of the effectiveness upon this model was conducted by using three instruments, namely:1) students' achievement;2) students' activities; 3) students' responses upon learning implementation. The study approaches were quantitative descriptive and qualitative. Data was collected through instrument, observation and interview with the respondents who were the 8th grade students at SMPN 10 Malang. The results showed that, 1) students' achievement score during conducting the research was 76.32%, which means it meets the criteria of model effectiveness; 2) the eigth aspects of students' activities lied on the categories which meet the requirements to conclude that learning model is effective, and 3) students' responses consisted of three aspects, namely interest, leading-edge and the level of ease in fulfiling the requirements of the effectiveness of learning model.