The use of mobile instant messaging (MIM), such as WhatsApp for learning can provide students with many benefits. With the recent switch to distance learning due to the COVID-19 outbreak, there is an ever growing reliance on information and communication technology for online teaching and learning. However, the increased use of MIM can also have consequences for students. This paper aims to explore the negative side of using WhatsApp during the shift to remote learning due to COVID-19. It investigates factors associated with WhatsApp use that cause fatigue among university students. Based on a review of the literature, it examines the effects of information and communication overload, invasion of life, and invasion of privacy on fatigue. It also examines the influence of fatigue on students’ performance. The data was collected via online questionnaires from 1188 undergraduate students in Saudi Arabia. The results indicate that the use of WhatsApp for learning creates fatigue among students. The reasons for the experience of fatigue are information and communication overload and invasion of privacy. The results also show that fatigue is negatively associated with students’ performance. The findings suggest that negative outcomes of MIM should be taken into account when designing distance learning