This study developed a research model of mobile voice communication on the basis of the social skills deficit hypothesis. In the model, poor social skills were related to less face-to-face and mobile voice communication, which was linked to greater loneliness. Structural equation modeling analyses of survey responses from 374 adults supported the social skills deficit hypothesis in that poor social skills were related to less involvement in face-to-face communication and greater loneliness. Also, as expected, more face-to-face interactions were associated with lower levels of loneliness; however, more cell phone calling was associated with greater loneliness. Additional regression analyses revealed that the positive relationship between mobile voice communication and loneliness was more pronounced for those who have more friends than those who have fewer friends.