Effective writing instruction is crucial for EFL learners. Nonetheless, teaching cause-and-effect
sentences remains a challenge. The current study aims to examine the effectiveness of puzzle media in
addressing this challenge. The study employed a pre-experimental, pre-test/post-test design with one
group of participants comprising Indonesian high school students. Specifically, this group underwent a
pre-test, instructional treatments using puzzle media, and a post-test, along with a questionnaire. The
pre-test and post-test were intended to gauge the effectiveness of puzzle media on cause-and-effect
sentences as reflected in the participants’ ability to use these constructions before vs. after receiving the
instructional treatments, whereas the questionnaire was intended to explore their views of the given
instructional treatment. The data, comprising the participants’ scores on the pre-test and post-test,
were analysed using a paired-sample t-test. Results reveal a significant difference between pre-test and
post-test scores, indicating that puzzle media is effective in teaching cause-and-effect sentences to EFL
learners. Furthermore, the analysis of the participants’ responses on the questionnaire indicates that
62.1% of participants found puzzle media engaging and helpful in writing tasks. This study concludes
that incorporating puzzle media into EFL writing instruction can enhance learners’ mastery of cause
and-effect sentences and foster a more engaging learning experience.