Some non-professional subtitling communities have succeeded in tailoring structures where newcomers learn from their peers using collaboration as a key to develop the necessary skills. These environments are compatible with the collaborative translator-training environment promoted by the social constructivist approach. This study intends to shed light on how non-professional collaborative environments could be used in translator training. An experiment was carried out in 2013 using Amara and aRGENTeaM, two non-professional subtitling communities, as training environments for seventeen undergraduate students of translation at the Universitat Rovira i Virgili in Tarragona, Spain. Each student was asked to translate for both Amara and aRGENTeaM, and to adapt to their translation guidelines and time constraints. The data was collected over three weeks. Questionnaires were designed to collect data on the participants’ opinions regarding non-professional subtitling and its quality, the participants’ attitude towards the phenomenon and the possibility of using these environments for translator training. Results show that participants see non-professional translation activities as engaging projects that could provide them with skills they will need in the future if they decide to become translators.