This paper gives a detailed account of an analysis carried out at the French National Skiing and Mountaineering School from August 2008 to June 2009 to assess the language needs of French mountain guides. A targeted literature review highlighted two main points to be taken into account in the design of this language needs analysis: target situations and insiders’ expert knowledge. Then, one hypothesis and two research questions were identified. Data gathering methods – including unstructured interviews, non-participant observation of the foreign language certification process and a questionnaire – allowed testing of the questions via triangulation (by sources and methods) to validate the results.