The objective of this research is to identify the effect of organizational active participation in IkatanPelajarMuhammadiyah (Muhammadiyah Student Association) and learning motivation toward student academic achievement at SMP Muhammadiyah 1 Kebumen, both partially and simultaneously. This research was a survey research with the total of 35 students who were the administrators of IPM at SMP Muhammadiyah 1 Kebumen. Data were compiled through questionnaire whose validity and reliability had been tested. The questionnaire was used to collect data regarding the student active participation in IPM and their learning motivation. Whereas document on student score report was used to collect data on student academic achievement. The data were analyzed using multiple linear regression (t test and F test), which was initiated by prerequisite analyses of normality test, multicollinearity test, and heteroscedasticity test. Once the data had been analyzed, the results were as the following: (1) the active participation in IPM gave significant and positive effect on student academic achievement at SMP Muhammadiyah 1 Kebumen (p=0.017); indicating that the higher student active participation in IPM is, the higher their academic achievement will be. (2) Learning motivation gave positive and significant effect on student academic achievement at SMP Muhammadiyah 1 Kebumen (p=0.000); indicating that the higher the learning motivation is, the higher student academic achievement will be. (3) the organizational active participation in IPM and learning motivation simultaneously gave positive and significant effect on student academic achievement at SMP Muhammadiyah 1 Kebumen (p=0.000); indicating that the higher the student organizational active participation in IPM is, when supported with a high learning motivation, the higher their academic achievement will be.