Microblogging networks can potentially increase reflection, learning, and collaboration among undergraduate students. The purpose of this study is to investigate whether the use of Twitter can enhance perceived learning and promote critical thinking, collaborative learning, and active student roles. The participants, 202 undergraduate students, enrolled on three different degree courses, were studying educational technology course modules. A quantitative, transversal, and retrospective methodology with an "ex post facto" design was applied. The use of Twitter led to an increase in both perceived learning and critical thinking among the majority of students, and in collaborative aspects of the teaching-learning process, as well as in active student roles. Experience of Twitter and its use in an educational context has therefore contributed to enhancing the quality of learning and the teaching-learning process itself.