The present study investigated the effects of mobile learning technologies on students' English listening skills in higher education in the Sultanate of Oman. Also, the study aimed to find out the difficulties students encounter while using mobile learning devices. The study population consisted of all intermediate level students at Shinas College of Technology in the Sultanate of Oman during the second semester of Foundation English Language Program during 2008. Two groups out of ten from the intermediate level of a total of 51 students represented the sample of the study. Twenty-six students in one of the selected groups represented the experimental group, which studied English listening skills using mobile learning devices (mobile phones and iPods). The twenty-five students in the other group represented the control group, which studied English listening skills using CD ROMs. Two types of instruments were used to explore researcher questions. First, an English listening proficiency test was used to measure students' listening performance following the completion of the experiment. Second, an attitude questionnaire was used to assess the students' attitude toward using mobile learning devices. The major findings of the study are as follows: • The results of the English listening proficiency test revealed a significant difference between the learners' performance of the experimental group and the learners' performance of the control group using independent sample t-test that favored the experimental group who studied English listening skill using mobile learning devices. This finding indicates that using mobile learning devices was effective at improving the learners' English listening skills. * *Moreover, using independent sample t-test, the results of the experiment revealed no significant differences between the learners' performance who used mobile phones and those who used iPods to study the English listening skills. • Following the completion of the study, the results of the attitude questionnaire revealed that learners showed a strong positive attitude toward learning listening skill using mobile learning devices. The most common problems encountered by the students during the experiment were that the speakers in the audio files speak very fast and that some files are not clear enough. These findings lead to a number of recommendations for teaching English listening skills as well as to recommend studies in the area of mobile learning.