This study aims to explore personal information management (PIM) practices of undergraduate university students on ubiquitous devices such as mobile phones. The purpose was to investigate the relationship between mobile self-efficacy and mobile-based PIM practices of the respondentsin terms of finding/re-finding, keeping and organizing information. This study was the offspring of a PhD project. The quantitative research design was used to conduct this study. Structured questionnaire was used to collect data from undergraduate students Regression analysis was applied to investigate the relationship between mobile self-efficacy and their mobile based PIM practices. The findings revealed that undergraduate students search, browse, and scan information through mobile phones. They used keywords, searched from recently opened file, and from send item to find/re-find information. They save their personal information in folders, use mobile applications, and take screen shot of information to keep it for future use. Current study reported “ Sharing as keeping ‘as a new phenomenon in mobile based personal information keeping (ubiquitous environment). This study also reported ‘ Ubiquity’ as an emerging trend in PIM among young generation. Study found positive correlations between mobile self-efficacy and mobile based PIM. Current study developed a model of mobile self-efficacy and PIM. Based on new phenomena “ sharing as keeping’ (which occurred in current study), a model “mobile based personal information keeping” may be developed. This study helps software developers of smartphones to develop mobile phone applications according to users’ needs. This study provides better understanding of PIM model (finding/re-finding, keeping and organizing information) through ubiquitous devices (smart phones). Although studies have been conducted to know the impact or relationship between mobile self-efficacy and PIM, but no comprehensive study has been conducted to explore the relationship between mobile self-efficacy and the holistic picture of mobile based PIM (finding/re-finding, keeping, and organizing information) especially in developing countries like Pakistan.