Purpose: This research paper explores the effect of using Twitter activities to support a blended learning course (75% in-class and 25% Twitter activities) on the achievement and attitudes of female students compared to 100% in-class learning. Design/methodology/approach: In the 2016 academic year, the researcher compared an experimental group (34 students) and a control group (34 students). The learning process of the experimental group was based on continuity between 2 hours of in-class learning and 1 hour of learning activities that were mediated by Twitter activities each week. The control group's experience was 100% in-class with no app mediation. Findings: The principal results of the study are that the students in the experimental group performed better than those in the control group on the achievement test, learning tracks and attitudes. Learning track analysis shows that the students in the experimental group had greater participation in different topics of discussion in the Twitter space than did the control group. Originality/value: This research paper is useful for readers, parents, students and schools in exploring the effectiveness of Twitter activities to support blended courses in higher studies.