In this article, we propose an analysis of the poem Llama de amor viva by John of the Cross and its French translation Flamme d’amour vive by Jacques Ancet. Therefore, we use the toolkit developed by Kees Coster in his From World to World. An Armamentarium for the Study of Poetic Discourse in Translation (2000). Our most important aim is to provide a detailed analysis that puts the translation centre stage and permits to present the translator’s choices in a structured way. First, we give some relevant information on the source and target texts and the extratextual translator. Then, following the guidelines proposed by Coster, we start by establishing a semantico-pragmatic skeleton of the text world of the translation, on the macrostructural level, that will serve also to draw a sketch of the text world of the source text. Subsequently, we propose a comparative analysis of the microstructural elements (syntax, lexicon, prosody, rhetoric, and intertextuality) in order to observe the substantial shifts produced on these levels. Finally, we relate those shifts to the semantico-pragmatic skeleton, in order to estimate, on the macrostructural level, the difference between the text world of the original and the text world of the translation. In the conclusion, we will dress a global evaluation of the tools proposed by Kees Coster.