INTRODUCTION: Medical applications help physicians to make more rapid and evidence based decisions that may provide better patient care. This study aimed to determine the extent to which smart phones and medical applications are integrated in the emergency department daily practice. METHOD: In a cross sectional study, a modified standard questionnaire (Payne et al.) consisting of demographic data and information regarding quality and quantity of smartphone and medical app utilization was sent to emergency-medicine residents and interns twice (two weeks apart), in January 2015. The questionnaire was put online using open access "Web-form Module" and the address of the web page was e-mailed along with a cover letter explaining the survey. Finally, responses were analyzed using descriptive statistics and SPSS 22 software. RESULTS: 65 cases participated (response rate 86%). The mean age of interns and residents were 25.03 ± 1.13 and 30.27 ± 4.68 years, respectively (p < 0.001). There was no significant difference between interns and residents in owning a smartphone (p = 0.5). Android was more popular than IOS (67.7% against 25.8%) and the most popular medical apps were Medscape and UpToDate, respectively. 38 (61.3%) of the respondents were using their apps more than once a day and mostly for drug information. English (83.9%), Persian (12.9%), and other languages (3.2%) were preferred languages for designing a medical software among the participants, respectively. CONCLUSION: The findings of present study showed that smartphones are very popular among Iranian interns and residents in emergency department and a substantial number of them own a smartphone and are using medical apps regularly in their clinical practice.