Term variation is frequently a translation problem that manifests itself at the intralanguage level -given the existence of different term variants for the same concept and at the inter-language level- as a result of different translation equivalents for a term. This article presents a proposal for the development of term variation competence in student translators and interpreters in the framework of a collaboration project between universities. The assignment consisted on documenting the VariMed term base, containing synonyms of diseases in Spanish and English, with term variants used in Chilean Spanish. A situated and collaborative teaching-learning environment was proposed, where students had to carry out a real-life assignment in a simulated professional environment. Throughout the project, students learned the methodology of ad hoc terminology management, and developed practical and theoretical knowledge about term variation and its management in translation. As a result, students created 1170 term records, 360 corresponding to variants not yet registered in VariMed. The teaching proposal was evaluated by means of a questionnaire and a self-evaluation report. The most problems were reported in the compilation of a Chilean Spanish medical corpus, the identification of term variants and the expert validation phase. Furthermore, students found the learning experience useful for their training as translators/interpreters and evaluated positively its situated nature, especially the collaboration between universities.