This research was aimed at investigating the effectiveness of Consult, Act, Share ( CASh) technique for teaching writing narrative text of the tenth grade students of SMK N 1 Kalibagor in academic year 2014/ 2015. This research used quasi experimental research. The participants of this research were the tenth grade students in SMK N 1 Kalibagor . The two classes were chosen as the experimental (X Atu 2) and control class (X Atu 1). The technique of data collection used tests namely pre- test and post- test. The result of assessment showed that the mean score of pre- test in experimental class was 61.56 and the mean score of post-test was 70.3. Meanwhile, the mean score of pre-test in control class was 65.3 and the mean score of post-test was 71.61. There was an improvement from pre- test to post-test as many as 8.74 in the experimental class. The progression in the control class was 6.01 from pre- test to post- test. The data was calculated by statistical formula. The t- test result was 3. 435 while the t- table with the significant level 0.05 in d.f 58 was 1.6751. Based on the data analysis, t- test was higher than t- table or 3.435 ≤ 1.6751, so that the CASh technique gave positive effect for teaching writing narrative text was accepted.