Objective: This study aims to understand the presentations of autism spectrum disorder (ASD) patients in a tertiary hospital's emergency department (ED) in Turkey, and the difficulties of families face in the ED. Method: Clinical characteristics of ASD patients who presented to the ED between 1 January 2015 and 15 November 2020 were obtained by retrospective file review. The caregivers of the patients who had presented to the ED in 2020 were interviewed by a phone call. Results: There were 740 applications of 224 patients (192 boys, 32 girls). Almost half of the patients were between 0 and 5 years old. Respiratory problems were the most common cause of admissions in all age groups. The second common reasons for ED visits were gastrointestinal problems in 0-5 years old, traumatic injuries/poisoning in 6-12 years old, and epilepsy/syncope in 13-17 years old. Psychiatric problems were less common (2.7%) than other reasons for admission. The most challenging issue for children was "the crowded waiting area, and the long waiting period" and followed by "physical restraint imposed on the child," "noise," and "bright light." Conclusion: As the clinicians' awareness and use of more accurate diagnostic tools have increased, the ASD prevalence has gradually increased. To increase the quality of healthcare services for these patients, awareness studies and new interventions are needed.