The quality of the treatment by emergency physicians of patients with abdominal complaints, who visited the emergency department (ED) of a city hospital (OLVG), Amsterdam, The Netherlands, was evaluated in a prospective observational study. During 6 months 1853 patients with abdominal complaints visited the emergency department of the OLVG hospital, 1221 patients (66%) without referral by a general practitioner (GP). Of these 1221 patients, 933 (76%) were treated by the emergency physician without consulting a specialist. Of these 933 patients, 814 were included in our follow-up study. A questionnaire was sent to them 1 week after visiting the ED. The response rate was 81% (663 patients). Of these 633 patients 48 patients sought medical help within 2 weeks after being discharged from the ED (38 patients in the same hospital and 10 patients in another hospital). Of these 48 patients, 17 were admitted to the hospital and 14 of them were operated on. After evaluation of these 17 patients we could conclude that seven patients were initially misdiagnosed by the emergency physician (1.1%). It is concluded that most patients with abdominal complaints visit the ED of this hospital without referral by their GP. Of these patients, the emergency physician can treat 76% without further specialist consultation. In seven patients (1.1%) the diagnosis was missed.