Personal mobile phone has become an integral part of our lives. In the medical field, the growing popularity of medicine applications allows more rapid communication among healthcare professionals and quick access to helpful information, which facilitates and improves patient care practice. The use of smartphones during work activities by healthcare professionals can cause a lack of attention and errors while carrying out health procedures. The result might be an increased threat endangering the safety of patients. The purpose of the present study was to investigate the level of nomophobia (a psychological condition regarded as a fear of being detached from mobile phone connectivity) and its correlations with the use of smartphones in clinical practice, distraction due to personal use and policies regarding mobile phones use in a sample of resident doctors of a University of Southern Italy. A cross-sectional study was carried out on 204 hospital residents divided into three areas depending on their duties: clinical, surgical, and services. Two tools were used: nomophobia questionnaire (NMP-Q) and a composite questionnaire investigating smartphone use in the specific healthcare setting. Sixty percent of participants were affected by a moderate level of nomophobia and 10% by a severe degree, jeopardizing both the work and social relationships of young doctors. Smartphone use can certainly represent a helpful support tool for clinical practice; consequently, we believe it would be appropriate to find instruments to screen smartphone dependence or compulsive use to further prevent, early diagnose or treat this detrimental disorder for health professionals.