Penelitian ini bertujuan untuk (1) menginvestigasi apakah ada peningkatan pencapaian berbicara sesudah diajar menggunakan teknik story completion, dan (2) menemukan aspek berbicara manakah yang paling meningkat setelah diajar menggunakan teknik story completion. Untuk mencapai tujuan ini, peneliti menggunakan studi kuantitatif yang melibatkan satu kelas. Instrumen untuk pengumpulan data dalam penelitian ini adalah tes berbicara dan rekaman. Penelitian ini menggunakan content and construct validity, dan juga inter-rater reliability untuk mengukur konsistensi tes. Hasil analisis data menunjukan bahwa terdapat peningkatan pencapaian berbicara siswa setelah diajar menggunakan teknik story completion. Kemudian, pemahaman adalah aspek yang paling meningkat diantara aspek yang lain. Hasil tes hipotesis menunjukan bahwa nilai signifikan (2- tailed) adalah 0.000 (p0.05). Dapat disimpulkan bahwa H0 ditolak dan menunjukan bahwa teknik story completion dapat meningkatkan kemampuan berbicara siswa di semua aspek terutama dalam aspek pemahaman.This study aimed at (1) finding out whether there was an increase of students speaking achievement after being taught through story completion technique, and (2) finding out the aspects of speaking of the students that increase most after being taught through story completion technique. The researcher carried out quantitative study with one group pretest posttest design, involving one class as experimental class. The instrument in this research was speaking test and recording. This study used content and construct validity, and also inter-rater realiability to measure the consistency of the test. The results of data analysis showed there was an increase of students speaking achievement after being taught through story completion technique. Then, comprehensibility increased the most of the other aspects of speaking. Hypothesis test showed that the significance value (2- tailed) was 0.000 (p0.05). It could be concluded that null-hypothesis was rejected, and it was inferred that story completion technique increase the students speaking in all aspects especially in comprehensibility.. Keywords: speaking, speaking achievement, story completion technique