This paper describes the development of Finnish linguistic resources for use in MedSLT, an Open Source medical domain speech-to-speech translation system. The paper describes the collection of the medical sub-domain corpora for Finnish, the creation of the Finnish generation grammar by adapting the original English grammar, the composition of the domain specific Finnish lexicon and the definition of interlingua to Finnish mapping rules for multilingual translation. It is shown that Finnish can be effectively introduced into the existing MedSLT framework and that despite the differences between English and Finnish, the Finnish grammar can be created by manual adaptation from the original English grammar. An initial evaluation of English to Finnish speech-to-speech translation is also presented.