This study examines the relationship between motivations for mobile phone use and social capital among mobile phone-savvy college students in Shanghai and Taipei. Our findings from the survey of 1,923 reveal some key differences. Specifically, the Shanghai respondents had a higher motivation for using the mobile phone for entertainment/relaxation and surveillance. Regarding the relationship between motivations for mobile phone use and social capital, results of multivariate analyses using the Shanghai sample show that entertainment and relaxation needs significantly predicted life satisfaction, while surveillance needs were significantly associated with leisure activity. In the Taipei sample, entertainment and relaxation needs significantly predicted leisure activity and life satisfaction. Finally the role of societal factors in accounting for these differences is discussed.