Objective: To determine the waiting time for admission (WTA) of patients to the adult emergency department (ED) of a tertiary hospital and to identify the factors associated with their delay. Methodology: Observational cross-sectional study that included patients older than 14 years admitted during four consecutive weeks (June 2018). We evaluated waiting time from triage to emergency discharge, time between first medical attention, indication for admission to the hospital ward and its completion; the reason for delay, age, sex, priority of care, destination area and admission diagnosis were evaluated. For statistical analysis, Mann Whitney U and Chi-square tests were applied according to type of data, using SPSS-IBM 25.0. Results: 380 patients were included, 51% female, median age 69 years (Inter quartile range 18.7), most frequent reasons for admission were respiratory infection 18% and...