Proficiency in English language depends on the knowledge of its vocabulary possessed by the second and foreign language learners and even the native speakers. Though developing the vocabulary is vital, it poses several problems, especially, to non-native students of English. Students with a low vocabulary knowledge show weak academic performance in different courses related to the language skills, linguistics, literature, and translation at the university level of education. This study, in particular, aims to investigate the problems faced by English majors in learning the vocabulary at Prince Stattam bin Abdulaziz University (PSAU) in Saudi Arabia. It also puts forward some vocabulary-learning strategies to minimize the potential problems. The data consist of the responses of 100 student-participants (undergraduates) randomly picked up from five different levels (four, five, six, seven, and eight) of 4-Year BA English Program at PSAU. This quantitative study uses an online questionnaire, as an instrument, to collect the data. The results reveal that the English majors at PSAU face several problems in learning the vocabulary such as knowing the meanings of new words, pronouncing new words, using new words correctly, memorizing and spelling new vocabulary and so on. To its contribution, this study emphasizes the importance of learning the English vocabulary, draws students' attention towards it, highlights the problems encountered by students, and raises their awareness of the vocabulary. Future research may explore teachers' perspectives on students' vocabulary-learning problems and instructional methods implemented to teach the vocabulary in English language classrooms.