This study explored secondary school teachers" confidence in English writing and their instructional approaches for teaching writing. The study also investigated the relationship between teachers" instructional choices in teaching writing and teacher variables, such as gender, major, teaching experience, writing proficiency, and types of schools they work for. Online survey was conducted with 116 English teachers working in different regions in Korea. The findings of the study indicated that teacher confidence in English writing and writing instruction differed according to their L2 writing proficiency. The more proficient in L2 writing, the more confident the teachers were. In addition, the teachers" tendency to teach to the CSAT differed according to school type. In other words, the degree of teaching to the test was found to be highest in regular high schools and lowest in middle schools. The study also found that teachers" writing-based instruction, instead of language-based instruction, predicted their confidence in writing and writing instruction, and vice versa. These findings of the study suggest the need to resolve the problems of the CSAT and to reform the educational system including classroom teaching and college admission exam.