A new didactic approach based on the so-called historical thinking or historical competency emerged a few years ago. The accessibility to a great variety of photographic records from different fields and the possibilities that provide the new educational technologies to work with photography make it an appropriate resource for the understanding of History through the engagement of different «historical competencies» in the classroom. Its effectiveness as a didactic material will depend on the strategies used. The dialogic approach and the didactic strategies linked to the main historical competencies are the two foundations that we proposed to obtain all the didactic potential from this type of material. The article presents some core ideas about competencies that allow the articulation of historical thinking: evaluation of evidence, construction of narratives, historical time and analysis of causality. Some didactic activities are proposed around them that illustrate how to work historical thinking through photography.