The aim of the current study is to evaluate poetry writing as a way of second language (L2) learning by exploring the interaction between academic prose and the effect of writing Japanese poetry — haiku. This article first describes some critiques of using poetry in educational settings and discusses the nature of poetry writing at the tertiary level in L2 contexts. The study was designed as an intervention in which 20 EFL students in Japan produced pre- and post-argumentative essays and L2 haikus. The data obtained was submitted to statistical analysis, which showed that there was a significant difference in the use of linguistic features between pre- and post-tests indicating that the task of writing haiku affected the EFL students' written performance in the post-argumentative essay. In addition, the L2 haiku corpus produced revealed the English haiku as short, personal, direct and descriptive poetry.