Abstract   This study analyses the translation of a technical guidebook in the subject field of hydropower generation. The aim is to identify and apply functional translation theories when translating general technical terms, industry terms and contract terms. The theoretical basis for the study consists of Eugene Nida’s and Vinay & Darbelnet’s models for translation as well as theories on terminology by Rune Ingo and Therésa Cabré. During the translation process, technical terms were identified and subsequently translated using one or more of the theories described. The result was then analysed and discussed. Although the study is not comprehensive enough to draw significant conclusions, the result indicates that in order to render the best possible translation of technical terms, a combination of theories and methods are best applied; direct translation regarding systematized terminology similar to general technical terms and oblique translation, or dynamic equivalence, regarding industry terms and contract terms. The results further suggest that structural analysis is of great value in order to determine the correct level of the term. In addition, the translator’s experience and knowledge of the subject field as well as readiness to consult parallel texts seem to be vital to the outcome of the translation.