Although acute appendicitis is often difficult to diagnose and negative laparotomy rates of 25 per cent are common, several options are currently available for the preoperative work-up. Careful history taking and physical examination are essential, together with analysis of inflammatory variables (C-reactive protein and white cell count). After admission, additional help is available in the form of ultrasonography and computerised tomography (CT), ultrasonography apparently being best in slender and normal weight patients (body mass indices < 25) and CT in overweight patients. The article reports how, without using invasive laparoscopy, a negative laparotomy rate of 7.2 per cent (11% in women and 4% in men) was obtained in 1998 at a hospital serving a population of 330,000.