This study examined the use of mobile phones to regulate negative emotions, considering both the role of different aspects of phone use and individual differences in emotion regulation strategies. A total of 287 young adult smartphone users completed an online survey that addressed use of mobile phones for negative emotion regulation. They responded to a phone loss scenario by rating how much they would miss various uses/functions of the phone (which could be involved in emotion regulation). Habitual use of reappraisal to regulate emotion was associated with missing both interpersonal contact and social support, but not access to entertainment/information. In contrast, habitual use of emotion suppression was associated only with missing entertainment/information content. Regulating negative emotions via mobile phone was associated with missing all three uses/functions of the phone, but perception that the phone was effective in remediating negative emotion was associated only with missing social support. Well-being was related to greater use and perceived effectiveness of the mobile phone for emotion regulation. Overall, this study demonstrates that mobile phones can yield psychological benefits, depending on how they are used. Findings suggest that using the phone for social support is most likely to lead to effective remediation of negative emotion. Interpretations and implications of the findings are discussed.