In this research was analysed 120 twelfth grade students' behaviour, of "Iulian Pop" Economic High School in Cluj-Napoca, Romania, regarding the use of the Facebook social network for learning and assessment in Geography. Students were organised in five discussion groups on the social network Facebook. To achieve the research objectives, we analysed students' answers at a questionnaire and the contents of the dialogue between teacher and students and also between students. Students perceived positively the learning and assessment activities and they perceived their teacher as their equal. At the cognitive level, the activity was focused on clarifying certain aspects, revision, knowledge learning and assessment. The disadvantages of the learning activity in the Facebook discussion group were that the posted materials cannot be classified and can be found with difficulty.