Learning is interwoven in daily life and so it can be take place at anytime and anywhere by using mobile device. In the 21st century, mobile devices have become ubiquitous, affordable and accessible for the teenagers. The teenagers have the opportunity to perform the learning activities by using the mobile devices. However, what are they used their mobile devices for? Many quantitative studies have been done for investigating the perception of technology use in education, but the studies done do not specifically focus on the use of mobile devices into ubiquitous learning by the teenager especially in Malaysia. Therefore, this research is conducted to obtain an in depth understanding of the usage pattern of the teenagers on their mobile devices and to clarify to what extent they used the mobile devices in performing learning activities. The study also analyzes the factors affecting the teenagers from using mobile devices to perform learning and provides a snapshot of how the teenagers perceive the use of mobile devices qualitatively. The study shows that teenagers possessed positive attitudes towards using mobile devices in performing ubiquitous learning. The teenagers perceived that the mobile devices can be used for gaming, entertainment as well as learning because they are very convenient, fast response and easy to use to access to knowledge of information. However, using mobile devices to perform ubiquitous learning is much depends on the individual's preference, interest and self-motivation. Learning facts, languages and skills using mobile devices are the most preferable activities among the teenagers.