Maths in-service Teacher Training and the Restructuring of Secondary Education in East-Timor

East Timor is undergoing a profound restructuring of its secondary education. For its success, it is crucial that foreign entities maintain their support regarding in-service training of secondary school teachers. In this context, we defined the following research questions: Under which conditions is in-service teacher training in Mathematics (Maths from this point onwards) being implemented in East Timor? How is it being done, mainly regarding the curricular materials produced - curriculum, syllabus, textbooks and teacher's guides? What are the trainer's representations of the secondary educational context and of the teachers’ pedagogical practices? We opted for a qualitative case study framed within a constructivist paradigm. Regarding the technique of data collection, we chose the inquiry through a semi-structured interview, informal conversations and the direct observation of training sessions, which were audio recorded. Data collected were submitted to content analysis, which was guided by categories that emerged from the research questions and objectives. As main results, we highlight that resources, beyond those produced in the scope of international cooperation, are still very scarce. The training course is mainly focused on the resolution of the tasks proposed in textbooks, though curricular, didactical and mathematical aspects are also discussed. The pedagogical practices of Timorese teachers are still based on a very traditional paradigm, but some changes are emerging. So, we can corroborate that change is a slow process, especially with regard to the educational context. In-service teacher training can be vital to support an adequate implementation of the restructuring of secondary education. However, many other initiatives need to be developed, from a macro (educational policies) to a micro school level.