The Alvarado score was assessed as to its accuracy in the preoperative diagnosis of acute appendicitis. A series of 49 consecutive patients was studied prospectively over a period of 9 months in two hepapitals (Gateshead and Sunderland). The presence of a high score was found to be an easy and satisfactory aid to early diagnosis of appendicitis in children and men. However, the false-positive rate for appendicitis in women was unacceptably high.