This study investigates the effectiveness of WhatsApp (WA) in helping students learn phrasal verbs in an English as a Foreign Language context. Using a mixed-method approach, data were collected from 32 Level 4 students of the General Foundation Program at the University of Technology and Applied Sciences, Ibra, Oman. The students were provided with 15 phrasal verbs to be learnt and used in sentences within five weeks through WA. An achievement test was conducted in the fifth week to measure the learning. In addition, a questionnaire survey and an interview were conducted to investigate students' perceptions regarding the effectiveness of WA in learning and the challenges they faced during the process. The findings showed students' positive perception regarding WA's effectiveness as a learning tool. However, certain challenges such as distraction, poor Internet connection, and poor time management were found to hinder their learning process considerably. Overall, the study highlighted the possibility of successful WA integration in foreign language education with strategies to minimize the challenges and maximize the effectiveness.