Introduction and Aims: The choice of the patient to leave the hospital before the physician discharges him is called discharge against medical advice (DAMA). The purpose of this study was to identify the characteristics of patients with DAMA and compare them with non-DAMA patients. Materials and Methods: This cross-sectional study was performed on all the patients discharged from the emergency department of Imam Reza Hospital in Mashhad in 2015. The patients' data were retrieved from their electronic medical records. After pre-processing, the data were finally analyzed using a frequency table and a chi-square test. All analyzes were performed using SPSS Statistics Version 22 software. Results: The total number of the eligible patients in the study was 19,313, of whom 6,993 were discharged against medical advice. The mean age of DAMA patients was 38.1 ± 19.34 years. 57% of DAMA patients were male; and being young, married, and lack of insurance were three major factors associated with DAMA. Other related factors were: Iranian nationality, rurality, residence in Mashhad, length of stay, admission- shift/ day/ month/ season. Consultation: Although the DAMA rate is low in this study (3.49%), it is very important to pay attention to this issue; because the risk of death and re-admission in DAMA patients is high. Therefore, identifying the general characteristics of these patients and determining the factors associated with DAMA can help decide on the selection of effective interventions to reduce DAMA rate.