The Muon Anomalous Magnetic Moment

The muon g-2 experiment at the Brookhaven National Laboratory is described, including its motivation, goal and present status. The latest result based on 1998 data is a(mu+) = g-2/2 =11 659 191(59) x 10(-10) (5 ppm), where the error is primarily statistical. This value agrees with the present theoretical value. Data obtained thus far and now being analyzed should have a statistical error of about 0.5 ppm.