Mobile devices have dramatically expanded in popularity and availability in people's daily lives and have become an essential component of the modern Educational paradigm. The purpose of this study was to examine the impact of using mobile learning on improving adult learners listening skills in the Omani context, to investigate their attitudes towards using Mobile-learning, and to explore the factors that stand as barriers to its implementation. The study is a quasi- experimental study and the sample consisted of 31 male Omani students enrolled in the foundation program at a military educational institute, divided into two classes. The experimental class had 15 students and the control one had 16 students. The two classes were randomly assigned among the five available classes in the current level of the foundation program. The control group students worked with the coursebook listening activities while the students in the experimental group worked with the listening activities following mobile-based instruction. Listening comprehension tests (Pre-test and Post-test) and an attitude questionnaire were administered to collect the needed data to answer the research questions. The results showed the effectiveness of contextualizing m-learning practice on improving listening skills and revealed the merits of the integration of mobile phones in a foreign language class. The major findings of this study are as follows: 1. There were statistically significant differences at (α≤0.05) level between the post-test mean scores of the experimental group taught listening skills by using mobile learning and the control group taught listening skills by conventional methods, in favour of the experimental group. 2. The participants had positive attitudes towards using mobile learning in improving their listening comprehension skills. They found that mobile learning enhanced their motivation, increased their exposure, expanded their vocabulary repertoire, and provided easy access to "anytime" and "everywhere" learning. 3. The participants in the study emphasized some challenges that were related to mobile software design, screen sizes of mobile phones, network connections, and the listening content. 4. The participants also suggested redesigning a new mobile software that meets users' needs and gives a better attention to the functionality, usability, operability, and attractiveness issues. Based on the findings, some educational implications and recommendations in this area are suggested.