The article aims to give a broad overview of the main formal characteristics of Estonian haiku and to compare it to its Japanese origin. The analysis is based on texts published in the literary magazine "Looming" from 1963-1998, and focuses on two main issues: the openness of the form (in Eco's sense) and the use of tropes. It also touches upon the different mechanisms for meaning generation in Estonian haiku. The use of tropes is analysed in the light of Yuri Lotman's notions of "rhetorical – anti-rhetorical culture" and "meta-trope". The author concludes that while Japanese haiku is an open text and the meanings are created between different texts rather than inside the text, Estonian authors tend to prescribe the possible associations of their text. Thus it can be said that a notion "haiku" refers to considerably different kinds of texts in Japanese and Estonian literature.