New curricular plans based on key competences create the need for new educational proposals that allow their development. This article describes a proposal to develop key competences through project-based learning. The project's objective is the creation of a digital video. The following study was carried out with students in their final two years of non-mandatory secondary-school, in the subject of "Physics and Chemistry". The students created didactic documentary videos describing different aspects of kinematics. The planning of the project focused on to involve the students in all steps of the process, in order to be able to evaluate the competences developed during each part of the project. The results showed an important improvement in both the digital and science competences. It was also shown that the necessary stages to create an audiovisual presentation involve the use of the competences related to communication, personal initiative or learning to learn; this provides an opportunity for the student to develop said capacities.