Abdominal pain (AP) is a common presenting complaint in emergency department (ED) patients. A 1972 study reported that unsupervised surgical residents in a university hospital ED were unable to make a specific diagnosis in 41% of 1,000 AP patients. In the intervening time, ED availability of diagnostic technology has increased, and the reference hospital acquired full-time emergency medicine (EM) faculty. To assess what changes occurred in the evaluation and epidemiology of AP, a similar study was done at the same hospital. The study design was a review of records of 1,000 consecutive ED patients with AP seen in 1993 at a 58,000-visit public Level I trauma center ED. The percentage of ED patients (4% to 5%) with AP was unchanged. Frequency of hospital admission dropped from 27.4% (1972) to 18.3% (1993). There was marked increase in the specificity of diagnoses, with only 24.9% in 1993 diagnosed as undifferentiated abdominal pain (UDAP). There were eight cases of missed appendicitis in 1972 and none in 1993. One 1993 patient with acute cholecystitis was initially misdiagnosed as having UDAP. Advances in technology and EM faculty presence were temporally associated with improved diagnostic accuracy in patients with AP in a university hospital ED. As compared with 20 years ago, fewer patients required hospitalization, more were assigned a specific diagnosis, and there were fewer cases of missed surgical disease.