Pembelajaran sains menjelaskan fenomena alam sekitar. Berdasarkan observasi di SMP N 1 Karangawen pembelajaran bersifat tekstual. Case study adalah metode yang mengurangi kesenjangan diantara teori dan praktik. Tujuan penelitian ini adalah mendeskripsikan efektivitas penerapan metode case study untuk mengoptimalkan hasil belajar siswa pada materi hama dan penyakit tumbuhan. Penelitian dilaksanakan di SMP N 1 Karangawen. Penelitian ini merupakan penelitian eksperimen dengan desain control group pretest-posttest design. Penentuan sampel dilakukan secara purposive sampling. Data yang diambil dalam penelitian ini adalah hasil belajar kognitif dan afektif (sikap), tanggapan siswa dan guru. Hasil belajar kognitif dan afektif dianalisis dengan uji t. Hasil penelitian menunjukkan n gain kelas eksperimen 0,53 sedangkan kelas kontrol 0,43 dan berbeda signifikan. Hasil belajar afektif (sikap) kelas eksperimen 53,26 sedangkan kontrol 45,79 dan berbeda signifikan. Siswa memberikan tanggapan positif 87 % sedangkan guru 80 % terhadap penerapan metode case study. Berdasarkan hasil analisis dan pembahasan, maka dapat disimpulkan bahwa penerapan metode case study efektif pada materi hama dan penyakit pada tumbuhan yang ditunjukkan rata – rata peningkatan hasil belajar kognitif dan afektif kelas eksperimen lebih besar daripada kelas kontrol dan berbeda signifikan, siswa dan guru memberikan tanggapan positif > 70 % terhadap penerapan metode case study untuk mengoptimalkan hasil belajar siswa kelas VIII di SMP N 1 Karangawen. The science learning is to explain the natural phenomenon surroundings. Based on the result in SMPN 1 Karangawen , the learning process is still textual. The case study recomended as a method to decrase the gap between theory and practice. This research is an exsperimental with pretest-posttes control group design. Sampling was done by purposive sampling. The purpose of this study was to describe the effectiveness of the application of case study method to optimize students learning outcomes in pests and plant diseases material.The research is done in SMP N 1 Karangawen. The data taken is the result of cognitive learning, affective learning outcomes ( attitudes ), the responses of students and teachers. The result showed that the average of the cognitive outcomes learning’s improvement in experimental class (0,53) and the control class (0,40) and significantly different. Affective learning outcomes, the students attitudes on enviromental awareness in exsperimental class is 53,26 and controls class 45,79 and significantly different. Students give positive responses 87 % and teacher 80 % on the application of the case study method. Based on the result it can be concluded the application of the case study method is effective on the pests and plant diseases material shows the average enhance in cognitive and affective learning outcomes eksperimental class more than control class and is significantly different, students and teachers responded positively > 70 % on the application using case study is method to optimize students learning outcomes of class VIII in SMP N 1 Karangawen.